https://www.youtube.com/@simonsfoundation en The Simons Foundation’s mission is to advance the frontiers of research in mathematics and the basic sciences.Co-founded in New York City by Jim and Marilyn Simons, the foundation exists to support basic — or discovery-driven — scientific research undertaken in the pursuit of understanding the phenomena of our world.The Simons Foundation’s support of science takes two forms: We support research by making grants to individual investigators and their projects through academic institutions, and, with the launch of the Flatiron Institute in 2016, we now conduct scientific research in-house, supporting teams of top computational scientists.Links:Simons Foundation: https://www.simonsfoundation.orgFlatiron Institute: https://www.simonsfoundation.org/flatiron/Simons Foundation Facebook: https://www.facebook.com/SimonsFoundationFlatiron Institute Facebook: https://www.facebook.com/FlatironInstitute/Simons Foundation Twitter: https://twitter.com/simonsfdnFlatiron Institute Twitter: https://twitter.com/flatironinst https://megaphone.imgix.net/podcasts/fa7034ac-d707-11f1-b91c-3fd9fe9c8e3c/image/f60cf536bb594f7a7d563894f20bcfd9.jpg?ixlib=rails-4.3.1&max-w=3000&max-h=3000&fit=crop&auto=format,compress https://www.youtube.com/@simonsfoundation no episodic Simons Foundation The Simons Foundation’s mission is to advance the frontiers of research in mathematics and the basic sciences.Co-founded in New York City by Jim and Marilyn Simons, the foundation exists to support basic — or discovery-driven — scientific research undertaken in the pursuit of understanding the phenomena of our world.The Simons Foundation’s support of science takes two forms: We support research by making grants to individual investigators and their projects through academic institutions, and, with the launch of the Flatiron Institute in 2016, we now conduct scientific research in-house, supporting teams of top computational scientists.Links:Simons Foundation: https://www.simonsfoundation.orgFlatiron Institute: https://www.simonsfoundation.org/flatiron/Simons Foundation Facebook: https://www.facebook.com/SimonsFoundationFlatiron Institute Facebook: https://www.facebook.com/FlatironInstitute/Simons Foundation Twitter: https://twitter.com/simonsfdnFlatiron Institute Twitter: https://twitter.com/flatironinst The Simons Foundation’s mission is to advance the frontiers of research in mathematics and the basic sciences.

Co-founded in New York City by Jim and Marilyn Simons, the foundation exists to support basic — or discovery-driven — scientific research undertaken in the pursuit of understanding the phenomena of our world.

The Simons Foundation’s support of science takes two forms: We support research by making grants to individual investigators and their projects through academic institutions, and, with the launch of the Flatiron Institute in 2016, we now conduct scientific research in-house, supporting teams of top computational scientists.

Links:
Simons Foundation: https://www.simonsfoundation.org
Flatiron Institute: https://www.simonsfoundation.org/flatiron/
Simons Foundation Facebook: https://www.facebook.com/SimonsFoundation
Flatiron Institute Facebook: https://www.facebook.com/FlatironInstitute/
Simons Foundation Twitter: https://twitter.com/simonsfdn
Flatiron Institute Twitter: https://twitter.com/flatironinst

]]> Simons Foundation wauntedlabrador7777@gmail.com Despite the fact that experimental neural scaling laws have substantially guided empirical progress in large-scale machine learning, no existing theory can quantitatively predict the exponents of these important laws for any modern LLM trained on natural languages. It is also unclear whether they can be beaten by training with other objectives. Matthieu Wyart will review the efforts of the collaboration in studying this phenomenon, including the first such theory in the case of data-limited scaling laws. Wyart will then introduce synthetic languages displaying a hidden hierarchy (a central notion in both linguistics and computer vision), and discuss how these languages are learnt by deep, but not shallow, nets. Scaling laws in these synthetic languages follow from the same principle as in natural languages when trained at the token level, but these languages can be learnt much more efficiently by machines predicting in an abstract space — justifying the success of joint embedding predictive architectures (JEPA) and other machines learning from their own latents.Uploaded 06-11-26For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/ Sun, 08 Nov 2026 04:00:00 -0000 full Simons Foundation Despite the fact that experimental neural scaling laws have substantially guided empirical progress in large-scale machine learning, no existing theory can quantitatively predict the exponents of these important laws for any modern LLM trained on natural languages. It is also unclear whether they can be beaten by training with other objectives. Matthieu Wyart will review the efforts of the collaboration in studying this phenomenon, including the first such theory in the case of data-limited scaling laws. Wyart will then introduce synthetic languages displaying a hidden hierarchy (a central notion in both linguistics and computer vision), and discuss how these languages are learnt by deep, but not shallow, nets. Scaling laws in these synthetic languages follow from the same principle as in natural languages when trained at the token level, but these languages can be learnt much more efficiently by machines predicting in an abstract space — justifying the success of joint embedding predictive architectures (JEPA) and other machines learning from their own latents.Uploaded 06-11-26For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/ Despite the fact that experimental neural scaling laws have substantially guided empirical progress in large-scale machine learning, no existing theory can quantitatively predict the exponents of these important laws for any modern LLM trained on natural languages. It is also unclear whether they can be beaten by training with other objectives. Matthieu Wyart will review the efforts of the collaboration in studying this phenomenon, including the first such theory in the case of data-limited scaling laws. Wyart will then introduce synthetic languages displaying a hidden hierarchy (a central notion in both linguistics and computer vision), and discuss how these languages are learnt by deep, but not shallow, nets. Scaling laws in these synthetic languages follow from the same principle as in natural languages when trained at the token level, but these languages can be learnt much more efficiently by machines predicting in an abstract space — justifying the success of joint embedding predictive architectures (JEPA) and other machines learning from their own latents.

Uploaded 06-11-26

For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/

]]> 3510 no How do modern neural networks evolve from randomly initialized weights toward a useful representation of the data? How does this proceed layerwise, and what role does the structure of attention play in the case of language models?Uploaded 06-11-26Collaboration progress on this central problem draws from diverse methods including dynamical mean field theory, spectral methods, tractable toy models, symmetry analysis, and stochastic dynamics. Eva Silverstein will review several inter-related results exhibiting explicitly how interpretable representations emerge. These encompass multiple stages of learning: the escape from an initially uninformative regime, the emergence of structured directions during training, and, in simplified hierarchical models, the layer-by-layer construction of increasingly useful features. The structured directions that emerge during the learning dynamics include novel ones introduced via symmetry breaking in attention, enabling models to amplify or suppress meaningful token and representation classes. For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/ Sun, 08 Nov 2026 03:00:00 -0000 full Simons Foundation How do modern neural networks evolve from randomly initialized weights toward a useful representation of the data? How does this proceed layerwise, and what role does the structure of attention play in the case of language models?Uploaded 06-11-26Collaboration progress on this central problem draws from diverse methods including dynamical mean field theory, spectral methods, tractable toy models, symmetry analysis, and stochastic dynamics. Eva Silverstein will review several inter-related results exhibiting explicitly how interpretable representations emerge. These encompass multiple stages of learning: the escape from an initially uninformative regime, the emergence of structured directions during training, and, in simplified hierarchical models, the layer-by-layer construction of increasingly useful features. The structured directions that emerge during the learning dynamics include novel ones introduced via symmetry breaking in attention, enabling models to amplify or suppress meaningful token and representation classes. For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/ How do modern neural networks evolve from randomly initialized weights toward a useful representation of the data? How does this proceed layerwise, and what role does the structure of attention play in the case of language models?

Uploaded 06-11-26

Collaboration progress on this central problem draws from diverse methods including dynamical mean field theory, spectral methods, tractable toy models, symmetry analysis, and stochastic dynamics. Eva Silverstein will review several inter-related results exhibiting explicitly how interpretable representations emerge. These encompass multiple stages of learning: the escape from an initially uninformative regime, the emergence of structured directions during training, and, in simplified hierarchical models, the layer-by-layer construction of increasingly useful features. The structured directions that emerge during the learning dynamics include novel ones introduced via symmetry breaking in attention, enabling models to amplify or suppress meaningful token and representation classes.

For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/

]]> 3295 no Virtual Fibring of Manifolds and GroupsOne can learn a lot about a compact manifold if one can show that it fibres over the circle - in essence, this allows us to view a static n-dimensional manifold as a manifold of dimension n-1 that evolves in time.Being fibred (over the circle) is a relatively rare property. It is much more common to be virtually fibred, that is, to admit a finite cover that is fibred. For example, it was the content of a conjecture of William Thurston, now two theorems by Ian Agol and Dani Wise, that all finite-volume hyperbolic 3-manifolds are virtually fibred; in fact, this property is extremely common among irreducible 3-manifolds.The situation is less clear in higher dimensions. On the obstruction side, we know that virtually fibred manifolds must have vanishing Euler characteristic. This immediately shows that compact hyperbolic manifolds in even dimensions will not be virtually fibred. A more involved obstruction comes from L2-homology: virtually fibred manifolds must be L2-acyclic.The motivation behind the research I will present lies in trying to find situations in which the vanishing of L2-homology is is not only necessary, but also sufficient for virtual fibring. It turns our that a lot more can be said if we replace aspherical manifolds by their homological cousins: Poincare duality groups. Concretely, if G is an n-dimensional Poincare-duality group over the rationals, and if G satisfies the RFRS property, then G is L2-acyclic if and only if there is a finite-index subgroup G0 of G and an epimorphism from G0 onto the integers such that its kernel is a Poincare-duality group over the rationals of dimension n-1. (This last theorem is joint with Sam Fisher and Giovanni Italiano.)The RFRS property was introduced in Agol's work on Thurston's conjecture. A countable group is RFRS if and only if it is residually {virtually abelian and poly-Z}. All compact special groups in the sense of Haglund-Wise satisfy this property, so there is a ready supply of RFRS groups, also among fundamental groups of hyperbolic manifolds in high dimensions.Uploaded 05-10-26 Sun, 08 Nov 2026 02:51:00 -0000 full Simons Foundation Virtual Fibring of Manifolds and GroupsOne can learn a lot about a compact manifold if one can show that it fibres over the circle - in essence, this allows us to view a static n-dimensional manifold as a manifold of dimension n-1 that evolves in time.Being fibred (over the circle) is a relatively rare property. It is much more common to be virtually fibred, that is, to admit a finite cover that is fibred. For example, it was the content of a conjecture of William Thurston, now two theorems by Ian Agol and Dani Wise, that all finite-volume hyperbolic 3-manifolds are virtually fibred; in fact, this property is extremely common among irreducible 3-manifolds.The situation is less clear in higher dimensions. On the obstruction side, we know that virtually fibred manifolds must have vanishing Euler characteristic. This immediately shows that compact hyperbolic manifolds in even dimensions will not be virtually fibred. A more involved obstruction comes from L2-homology: virtually fibred manifolds must be L2-acyclic.The motivation behind the research I will present lies in trying to find situations in which the vanishing of L2-homology is is not only necessary, but also sufficient for virtual fibring. It turns our that a lot more can be said if we replace aspherical manifolds by their homological cousins: Poincare duality groups. Concretely, if G is an n-dimensional Poincare-duality group over the rationals, and if G satisfies the RFRS property, then G is L2-acyclic if and only if there is a finite-index subgroup G0 of G and an epimorphism from G0 onto the integers such that its kernel is a Poincare-duality group over the rationals of dimension n-1. (This last theorem is joint with Sam Fisher and Giovanni Italiano.)The RFRS property was introduced in Agol's work on Thurston's conjecture. A countable group is RFRS if and only if it is residually {virtually abelian and poly-Z}. All compact special groups in the sense of Haglund-Wise satisfy this property, so there is a ready supply of RFRS groups, also among fundamental groups of hyperbolic manifolds in high dimensions.Uploaded 05-10-26 Virtual Fibring of Manifolds and Groups

One can learn a lot about a compact manifold if one can show that it fibres over the circle - in essence, this allows us to view a static n-dimensional manifold as a manifold of dimension n-1 that evolves in time.Being fibred (over the circle) is a relatively rare property. It is much more common to be virtually fibred, that is, to admit a finite cover that is fibred. For example, it was the content of a conjecture of William Thurston, now two theorems by Ian Agol and Dani Wise, that all finite-volume hyperbolic 3-manifolds are virtually fibred; in fact, this property is extremely common among irreducible 3-manifolds.The situation is less clear in higher dimensions. On the obstruction side, we know that virtually fibred manifolds must have vanishing Euler characteristic. This immediately shows that compact hyperbolic manifolds in even dimensions will not be virtually fibred. A more involved obstruction comes from L2-homology: virtually fibred manifolds must be L2-acyclic.The motivation behind the research I will present lies in trying to find situations in which the vanishing of L2-homology is is not only necessary, but also sufficient for virtual fibring. It turns our that a lot more can be said if we replace aspherical manifolds by their homological cousins: Poincare duality groups. Concretely, if G is an n-dimensional Poincare-duality group over the rationals, and if G satisfies the RFRS property, then G is L2-acyclic if and only if there is a finite-index subgroup G0 of G and an epimorphism from G0 onto the integers such that its kernel is a Poincare-duality group over the rationals of dimension n-1. (This last theorem is joint with Sam Fisher and Giovanni Italiano.)The RFRS property was introduced in Agol's work on Thurston's conjecture. A countable group is RFRS if and only if it is residually {virtually abelian and poly-Z}. All compact special groups in the sense of Haglund-Wise satisfy this property, so there is a ready supply of RFRS groups, also among fundamental groups of hyperbolic manifolds in high dimensions.

Uploaded 05-10-26

]]> 2945 no Training modern AI systems is increasingly expensive, yet many of the choices that determine this cost still depend on extensive empirical search. This talk will review how combining ideas from theoretical physics with targeted experiments make large-scale training more predictable, transferable, and efficient. Cengiz Pehlevan will begin by examining how parameterization and hyperparameter choices shape optimization dynamics. Pehlevan will then show how this understanding can guide the design of training schedules, emerging optimizers, and architectures. Throughout, Pehlevan will highlight the resulting empirical gains and the adoption of these ideas in industry.Uploaded 06-11-26For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/ Sun, 08 Nov 2026 02:00:00 -0000 full Simons Foundation Training modern AI systems is increasingly expensive, yet many of the choices that determine this cost still depend on extensive empirical search. This talk will review how combining ideas from theoretical physics with targeted experiments make large-scale training more predictable, transferable, and efficient. Cengiz Pehlevan will begin by examining how parameterization and hyperparameter choices shape optimization dynamics. Pehlevan will then show how this understanding can guide the design of training schedules, emerging optimizers, and architectures. Throughout, Pehlevan will highlight the resulting empirical gains and the adoption of these ideas in industry.Uploaded 06-11-26For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/ Training modern AI systems is increasingly expensive, yet many of the choices that determine this cost still depend on extensive empirical search. This talk will review how combining ideas from theoretical physics with targeted experiments make large-scale training more predictable, transferable, and efficient. Cengiz Pehlevan will begin by examining how parameterization and hyperparameter choices shape optimization dynamics. Pehlevan will then show how this understanding can guide the design of training schedules, emerging optimizers, and architectures. Throughout, Pehlevan will highlight the resulting empirical gains and the adoption of these ideas in industry.

Uploaded 06-11-26

For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/

]]> 3703 no Classical statistical models are constructed so that either the number of parameters is small with respect to the sample size, or the regularization is strong enough so that their “effective dimension” is small. In contrast, modern machine learning models are vastly miss-specified and overparametrized, and only very loosely regularized. These models are learnt using empirical risk minimization, but the empirical risk function has many near-global optima which are very far from each other in parameter space. How can we make sense of the good statistical properties of these models? Andrea Montanari will summarize what we learned over the years by studying a simple and yet extremely rich setting: learning in two-layer networks.Uploaded 06-11-26For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/ Sun, 08 Nov 2026 01:00:00 -0000 full Simons Foundation Classical statistical models are constructed so that either the number of parameters is small with respect to the sample size, or the regularization is strong enough so that their “effective dimension” is small. In contrast, modern machine learning models are vastly miss-specified and overparametrized, and only very loosely regularized. These models are learnt using empirical risk minimization, but the empirical risk function has many near-global optima which are very far from each other in parameter space. How can we make sense of the good statistical properties of these models? Andrea Montanari will summarize what we learned over the years by studying a simple and yet extremely rich setting: learning in two-layer networks.Uploaded 06-11-26For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/ Classical statistical models are constructed so that either the number of parameters is small with respect to the sample size, or the regularization is strong enough so that their “effective dimension” is small. In contrast, modern machine learning models are vastly miss-specified and overparametrized, and only very loosely regularized. These models are learnt using empirical risk minimization, but the empirical risk function has many near-global optima which are very far from each other in parameter space. How can we make sense of the good statistical properties of these models? Andrea Montanari will summarize what we learned over the years by studying a simple and yet extremely rich setting: learning in two-layer networks.

Uploaded 06-11-26

For more information please visit: https://www.simonsfoundation.org/events/simons-collaboration-on-the-physics-of-learning-and-neural-computation-annual-meeting-2026/

]]> 3949 no In this Presidential Lecture, Sonya Hanson will discuss the ongoing journey to understand biological temperature sensing — a process that inherently relies on molecules changing shape as a function of small temperature changes. She will highlight how this puzzle has motivated community challenges and methods development to better capture the full conformational landscape of molecules from cryo-EM data. Combined with molecular simulation and recent innovations in machine learning, these technological developments are shifting our focus from rigid structures to dynamic ensembles and refining our ability to see how proteins function.Uploaded 26-10-26 Sun, 08 Nov 2026 00:00:00 -0000 full Simons Foundation In this Presidential Lecture, Sonya Hanson will discuss the ongoing journey to understand biological temperature sensing — a process that inherently relies on molecules changing shape as a function of small temperature changes. She will highlight how this puzzle has motivated community challenges and methods development to better capture the full conformational landscape of molecules from cryo-EM data. Combined with molecular simulation and recent innovations in machine learning, these technological developments are shifting our focus from rigid structures to dynamic ensembles and refining our ability to see how proteins function.Uploaded 26-10-26 In this Presidential Lecture, Sonya Hanson will discuss the ongoing journey to understand biological temperature sensing — a process that inherently relies on molecules changing shape as a function of small temperature changes. She will highlight how this puzzle has motivated community challenges and methods development to better capture the full conformational landscape of molecules from cryo-EM data. Combined with molecular simulation and recent innovations in machine learning, these technological developments are shifting our focus from rigid structures to dynamic ensembles and refining our ability to see how proteins function.

Uploaded 26-10-26

]]> 3752 no Spaghetti Code Assemblyhttp://www.simonsfoundation.org/multimedia/geometry-of-spaghetti-code/Uploaded 22-05-14 Sat, 07 Nov 2026 23:00:00 -0000 full Simons Foundation Spaghetti Code Assemblyhttp://www.simonsfoundation.org/multimedia/geometry-of-spaghetti-code/Uploaded 22-05-14 Spaghetti Code Assembly

http://www.simonsfoundation.org/multimedia/geometry-of-spaghetti-code/

Uploaded 22-05-14

]]> 668 no Probabilistic Models for Galois GroupsA fundamental object in number theory is the absolute Galois group of a number field, that is, the Galois group of the maximum algebraic extension. However, it is difficult to understand the structure of this group. Even smaller quotients of it, like the ideal class group, which is known to equal the Galois group of the maximum abelian unramified extension, can be difficult to describe. The Cohen-Lenstra program, beginning with work of Cohen and Lenstra and continued by many others, aims to describe the class group in a conjectural, probabilistic way: For a suitable notion of a random number field, calculate the probability distribution of the class group of a random number field as a distribution on the set of isomorphism classes of finite abelian groups. The non-abelian Cohen-Lenstra program aims to generalize this to other natural quotients of the absolute Galois group. I will discuss some progress in the non-abelian Cohen-Lenstra program and what it tells us about Galois groups.Uploaded 05-10-26 Sat, 07 Nov 2026 22:00:00 -0000 full Simons Foundation Probabilistic Models for Galois GroupsA fundamental object in number theory is the absolute Galois group of a number field, that is, the Galois group of the maximum algebraic extension. However, it is difficult to understand the structure of this group. Even smaller quotients of it, like the ideal class group, which is known to equal the Galois group of the maximum abelian unramified extension, can be difficult to describe. The Cohen-Lenstra program, beginning with work of Cohen and Lenstra and continued by many others, aims to describe the class group in a conjectural, probabilistic way: For a suitable notion of a random number field, calculate the probability distribution of the class group of a random number field as a distribution on the set of isomorphism classes of finite abelian groups. The non-abelian Cohen-Lenstra program aims to generalize this to other natural quotients of the absolute Galois group. I will discuss some progress in the non-abelian Cohen-Lenstra program and what it tells us about Galois groups.Uploaded 05-10-26 Probabilistic Models for Galois Groups

A fundamental object in number theory is the absolute Galois group of a number field, that is, the Galois group of the maximum algebraic extension. However, it is difficult to understand the structure of this group. Even smaller quotients of it, like the ideal class group, which is known to equal the Galois group of the maximum abelian unramified extension, can be difficult to describe. The Cohen-Lenstra program, beginning with work of Cohen and Lenstra and continued by many others, aims to describe the class group in a conjectural, probabilistic way: For a suitable notion of a random number field, calculate the probability distribution of the class group of a random number field as a distribution on the set of isomorphism classes of finite abelian groups. The non-abelian Cohen-Lenstra program aims to generalize this to other natural quotients of the absolute Galois group. I will discuss some progress in the non-abelian Cohen-Lenstra program and what it tells us about Galois groups.

Uploaded 05-10-26

]]> 2683 no More details: https://www.simonsfoundation.org/event/black-hole-collisions-the-extreme-side-of-gravity/Uploaded 30-09-19 Sat, 07 Nov 2026 21:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/black-hole-collisions-the-extreme-side-of-gravity/Uploaded 30-09-19 More details: https://www.simonsfoundation.org/event/black-hole-collisions-the-extreme-side-of-gravity/

Uploaded 30-09-19

]]> 3574 no ThresholdsI will discuss threshold phenomena for increasing properties under product measure, focusing on three related directions. The Kahn-Kalai conjecture, now resolved, compares the threshold of an increasing family with its expectation threshold up to a logarithmic factor. I will describe this result and its fractional relaxation, where spread measures provide a useful dual language. I will then turn to two open directions: the “second” Kahn--Kalai conjecture for graph containment, which asks whether the abstract expectation threshold can be replaced by the graphic expectation threshold, and Talagrand’s discrete convexity conjecture, whose reformulation via k-thresholds leads to graph decomposition questions.Uploaded 05-10-26 Sat, 07 Nov 2026 20:00:00 -0000 full Simons Foundation ThresholdsI will discuss threshold phenomena for increasing properties under product measure, focusing on three related directions. The Kahn-Kalai conjecture, now resolved, compares the threshold of an increasing family with its expectation threshold up to a logarithmic factor. I will describe this result and its fractional relaxation, where spread measures provide a useful dual language. I will then turn to two open directions: the “second” Kahn--Kalai conjecture for graph containment, which asks whether the abstract expectation threshold can be replaced by the graphic expectation threshold, and Talagrand’s discrete convexity conjecture, whose reformulation via k-thresholds leads to graph decomposition questions.Uploaded 05-10-26 Thresholds

I will discuss threshold phenomena for increasing properties under product measure, focusing on three related directions. The Kahn-Kalai conjecture, now resolved, compares the threshold of an increasing family with its expectation threshold up to a logarithmic factor. I will describe this result and its fractional relaxation, where spread measures provide a useful dual language. I will then turn to two open directions: the “second” Kahn--Kalai conjecture for graph containment, which asks whether the abstract expectation threshold can be replaced by the graphic expectation threshold, and Talagrand’s discrete convexity conjecture, whose reformulation via k-thresholds leads to graph decomposition questions.

Uploaded 05-10-26

]]> 2777 no More details: https://www.simonsfoundation.org/event/class-song-workshop/Uploaded 30-08-19 Sat, 07 Nov 2026 19:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/class-song-workshop/Uploaded 30-08-19 More details: https://www.simonsfoundation.org/event/class-song-workshop/

Uploaded 30-08-19

]]> 4200 no More details: https://www.simonsfoundation.org/event/dark-matter-heats-up-in-dwarf-galaxies/Uploaded 10-10-19 Sat, 07 Nov 2026 19:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/dark-matter-heats-up-in-dwarf-galaxies/Uploaded 10-10-19 More details: https://www.simonsfoundation.org/event/dark-matter-heats-up-in-dwarf-galaxies/

Uploaded 10-10-19

]]> 3495 no Nonparametric Inference Under Shape Constraints: Past, Present and FutureTraditionally, we think of statistical methods as being divided into parametric approaches, which can be restrictive, but where estimation is typically straightforward (e.g.~using maximum likelihood), and nonparametric methods, which are more flexible but often require careful choices of tuning parameters. Nonparametric inference under shape constraints sits somewhere in the middle, seeking in some ways the best of both worlds. I will provide a historical overview of the field, as well as a perspective on its current state, concluding with some thoughts on future directions and open problems.Uploaded 05-10-26 Sat, 07 Nov 2026 18:00:00 -0000 full Simons Foundation Nonparametric Inference Under Shape Constraints: Past, Present and FutureTraditionally, we think of statistical methods as being divided into parametric approaches, which can be restrictive, but where estimation is typically straightforward (e.g.~using maximum likelihood), and nonparametric methods, which are more flexible but often require careful choices of tuning parameters. Nonparametric inference under shape constraints sits somewhere in the middle, seeking in some ways the best of both worlds. I will provide a historical overview of the field, as well as a perspective on its current state, concluding with some thoughts on future directions and open problems.Uploaded 05-10-26 Nonparametric Inference Under Shape Constraints: Past, Present and Future

Traditionally, we think of statistical methods as being divided into parametric approaches, which can be restrictive, but where estimation is typically straightforward (e.g.~using maximum likelihood), and nonparametric methods, which are more flexible but often require careful choices of tuning parameters. Nonparametric inference under shape constraints sits somewhere in the middle, seeking in some ways the best of both worlds. I will provide a historical overview of the field, as well as a perspective on its current state, concluding with some thoughts on future directions and open problems.

Uploaded 05-10-26

]]> 2796 no More details: https://www.simonsfoundation.org/event/quantum-cafe-pablo-jarillo-herrero/Uploaded 10-10-19 Sat, 07 Nov 2026 17:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/quantum-cafe-pablo-jarillo-herrero/Uploaded 10-10-19 More details: https://www.simonsfoundation.org/event/quantum-cafe-pablo-jarillo-herrero/

Uploaded 10-10-19

]]> 4537 no Complexity of Submanifolds, Mean Curvature and SingularitiesI will survey some recent developments in mean curvature flow and minimal submanifold theory related to understanding the simplest singularities of these geometric variational problems. This is linked with broader questions about quantifying the complexity of submanifolds.Uploaded 05-10-26 Sat, 07 Nov 2026 16:00:00 -0000 full Simons Foundation Complexity of Submanifolds, Mean Curvature and SingularitiesI will survey some recent developments in mean curvature flow and minimal submanifold theory related to understanding the simplest singularities of these geometric variational problems. This is linked with broader questions about quantifying the complexity of submanifolds.Uploaded 05-10-26 Complexity of Submanifolds, Mean Curvature and Singularities

I will survey some recent developments in mean curvature flow and minimal submanifold theory related to understanding the simplest singularities of these geometric variational problems. This is linked with broader questions about quantifying the complexity of submanifolds.

Uploaded 05-10-26

]]> 2947 no More details: https://www.simonsfoundation.org/event/quantum-cafe-andrea-damascelli/Uploaded 10-10-19 Sat, 07 Nov 2026 15:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/quantum-cafe-andrea-damascelli/Uploaded 10-10-19 More details: https://www.simonsfoundation.org/event/quantum-cafe-andrea-damascelli/

Uploaded 10-10-19

]]> 3950 no Compatible Numerical Schemes for Thermodynamically Compatible Systems of Hyperbolic Partial Differential EquationsUploaded 05-10-26In this contribution two recent types of compatible numerical discretizations for overdetermined, thermodynamically compatible systems of hyperbolic partial differential equations (PDE) are discussed. Overdetermined hyperbolic and thermodynamically compatible (HTC) systems satisfy an additional extra conservation law for the total energy density, which is a consequence of all the other equations and which corresponds to the first principle of thermodynamics. The second principle of thermodynamics is contained in the entropy inequality, if present in the governing PDE system under consideration. Very often, such systems are also endowed with stationary differential constraints (involutions), such as the divergence-free condition of the magnetic field in the Maxwell equations or the curl-free condition of the velocity field in the equations of linear acoustics. Preserving at least one of the two aforementioned additional structural properties of the governing PDE system exactly at the discrete level is the major objective of the present paper. The first type of numerical schemes achieves compatibility with the extra conservation law for the total energy for a very general class of nonlinear hyperbolic PDE systems, but does not satisfy additional stationary differential constraints. The second scheme is compatible with the extra conservation law and preserves involutions exactly at the discrete level, but only for a very particular class of problems. The design of compatible numerical schemes for general nonlinear hyperbolic systems which satisfy both structural properties at the same time is still the subject of ongoing and future research. Sat, 07 Nov 2026 14:00:00 -0000 full Simons Foundation Compatible Numerical Schemes for Thermodynamically Compatible Systems of Hyperbolic Partial Differential EquationsUploaded 05-10-26In this contribution two recent types of compatible numerical discretizations for overdetermined, thermodynamically compatible systems of hyperbolic partial differential equations (PDE) are discussed. Overdetermined hyperbolic and thermodynamically compatible (HTC) systems satisfy an additional extra conservation law for the total energy density, which is a consequence of all the other equations and which corresponds to the first principle of thermodynamics. The second principle of thermodynamics is contained in the entropy inequality, if present in the governing PDE system under consideration. Very often, such systems are also endowed with stationary differential constraints (involutions), such as the divergence-free condition of the magnetic field in the Maxwell equations or the curl-free condition of the velocity field in the equations of linear acoustics. Preserving at least one of the two aforementioned additional structural properties of the governing PDE system exactly at the discrete level is the major objective of the present paper. The first type of numerical schemes achieves compatibility with the extra conservation law for the total energy for a very general class of nonlinear hyperbolic PDE systems, but does not satisfy additional stationary differential constraints. The second scheme is compatible with the extra conservation law and preserves involutions exactly at the discrete level, but only for a very particular class of problems. The design of compatible numerical schemes for general nonlinear hyperbolic systems which satisfy both structural properties at the same time is still the subject of ongoing and future research. Compatible Numerical Schemes for Thermodynamically Compatible Systems of Hyperbolic Partial Differential Equations

Uploaded 05-10-26

In this contribution two recent types of compatible numerical discretizations for overdetermined, thermodynamically compatible systems of hyperbolic partial differential equations (PDE) are discussed. Overdetermined hyperbolic and thermodynamically compatible (HTC) systems satisfy an additional extra conservation law for the total energy density, which is a consequence of all the other equations and which corresponds to the first principle of thermodynamics. The second principle of thermodynamics is contained in the entropy inequality, if present in the governing PDE system under consideration. Very often, such systems are also endowed with stationary differential constraints (involutions), such as the divergence-free condition of the magnetic field in the Maxwell equations or the curl-free condition of the velocity field in the equations of linear acoustics. Preserving at least one of the two aforementioned additional structural properties of the governing PDE system exactly at the discrete level is the major objective of the present paper. The first type of numerical schemes achieves compatibility with the extra conservation law for the total energy for a very general class of nonlinear hyperbolic PDE systems, but does not satisfy additional stationary differential constraints. The second scheme is compatible with the extra conservation law and preserves involutions exactly at the discrete level, but only for a very particular class of problems. The design of compatible numerical schemes for general nonlinear hyperbolic systems which satisfy both structural properties at the same time is still the subject of ongoing and future research.

]]> 2920 no More details: https://www.simonsfoundation.org/event/ccq-seminar-david-hollman/Uploaded 10-10-19 Sat, 07 Nov 2026 13:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/ccq-seminar-david-hollman/Uploaded 10-10-19 More details: https://www.simonsfoundation.org/event/ccq-seminar-david-hollman/

Uploaded 10-10-19

]]> 3457 no Measure Rigidity Beyond Homogeneous DynamicsWe describe recent work that extends some of the measure and topological rigidity results in dynamical systems from situations homogeneous under a Lie group to quite general manifolds.Uploaded 05-10-26 Sat, 07 Nov 2026 12:51:00 -0000 full Simons Foundation Measure Rigidity Beyond Homogeneous DynamicsWe describe recent work that extends some of the measure and topological rigidity results in dynamical systems from situations homogeneous under a Lie group to quite general manifolds.Uploaded 05-10-26 Measure Rigidity Beyond Homogeneous Dynamics

We describe recent work that extends some of the measure and topological rigidity results in dynamical systems from situations homogeneous under a Lie group to quite general manifolds.

Uploaded 05-10-26

]]> 2795 no The Orbit Method, Microlocal Analysis and Applications to L-FunctionsL-functions are generalizations of the Riemann zeta function. Their analytic properties control the asymptotic behavior of prime numbers in various refined senses. Conjecturally, every L-function is a "standard L-function" arising from an automorphic form. A problem of recurring interest, with widespread applications, has been to establish nontrivial bounds for L-functions. I will survey some recent results addressing this problem. The proofs involve the analysis of integrals of automorphic forms, approached through the lens of representation theory. I will emphasize the role played by the orbit method, developed in a quantitative form along the lines of microlocal analysis, as well as inputs from the theory of homogeneous dynamics and effective equidistribution.Uploaded 05-10-26 Sat, 07 Nov 2026 12:00:00 -0000 full Simons Foundation The Orbit Method, Microlocal Analysis and Applications to L-FunctionsL-functions are generalizations of the Riemann zeta function. Their analytic properties control the asymptotic behavior of prime numbers in various refined senses. Conjecturally, every L-function is a "standard L-function" arising from an automorphic form. A problem of recurring interest, with widespread applications, has been to establish nontrivial bounds for L-functions. I will survey some recent results addressing this problem. The proofs involve the analysis of integrals of automorphic forms, approached through the lens of representation theory. I will emphasize the role played by the orbit method, developed in a quantitative form along the lines of microlocal analysis, as well as inputs from the theory of homogeneous dynamics and effective equidistribution.Uploaded 05-10-26 The Orbit Method, Microlocal Analysis and Applications to L-Functions

L-functions are generalizations of the Riemann zeta function. Their analytic properties control the asymptotic behavior of prime numbers in various refined senses. Conjecturally, every L-function is a "standard L-function" arising from an automorphic form. A problem of recurring interest, with widespread applications, has been to establish nontrivial bounds for L-functions. I will survey some recent results addressing this problem. The proofs involve the analysis of integrals of automorphic forms, approached through the lens of representation theory. I will emphasize the role played by the orbit method, developed in a quantitative form along the lines of microlocal analysis, as well as inputs from the theory of homogeneous dynamics and effective equidistribution.

Uploaded 05-10-26

]]> 2802 no More details: https://www.simonsfoundation.org/event/gothamfest/Uploaded 10-10-19 Sat, 07 Nov 2026 11:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/gothamfest/Uploaded 10-10-19 More details: https://www.simonsfoundation.org/event/gothamfest/

Uploaded 10-10-19

]]> 2452 no Rationality of HypersurfacesA classical question in algebraic geometry is to determine which varieties, and in particular, which hypersurfaces, are rational or at least satisfy one of the weaker notions such as unirationality, retract rationality or stable rationality. This essentially amounts to asking whether (almost) all solutions of a given polynomial equation can be parametrized by rational functions. It is therefore a basic question about the solvability of polynomial equations. In this talk, I will present some results and open questions in this area. The techniques used range from algebraic cycles, quadratic forms and unramified cohomology to combinatorics and regular matroids. Some of the results presented will be based on joint work with J. Lange and on joint work with P. Engel and O. de Gaay Fortman.Uploaded 05-10-26 Sat, 07 Nov 2026 10:00:00 -0000 full Simons Foundation Rationality of HypersurfacesA classical question in algebraic geometry is to determine which varieties, and in particular, which hypersurfaces, are rational or at least satisfy one of the weaker notions such as unirationality, retract rationality or stable rationality. This essentially amounts to asking whether (almost) all solutions of a given polynomial equation can be parametrized by rational functions. It is therefore a basic question about the solvability of polynomial equations. In this talk, I will present some results and open questions in this area. The techniques used range from algebraic cycles, quadratic forms and unramified cohomology to combinatorics and regular matroids. Some of the results presented will be based on joint work with J. Lange and on joint work with P. Engel and O. de Gaay Fortman.Uploaded 05-10-26 Rationality of Hypersurfaces

A classical question in algebraic geometry is to determine which varieties, and in particular, which hypersurfaces, are rational or at least satisfy one of the weaker notions such as unirationality, retract rationality or stable rationality. This essentially amounts to asking whether (almost) all solutions of a given polynomial equation can be parametrized by rational functions. It is therefore a basic question about the solvability of polynomial equations. In this talk, I will present some results and open questions in this area. The techniques used range from algebraic cycles, quadratic forms and unramified cohomology to combinatorics and regular matroids. Some of the results presented will be based on joint work with J. Lange and on joint work with P. Engel and O. de Gaay Fortman.

Uploaded 05-10-26

]]> 2767 no More details: https://www.simonsfoundation.org/event/gothamfest/Uploaded 10-10-19 Sat, 07 Nov 2026 09:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/gothamfest/Uploaded 10-10-19 More details: https://www.simonsfoundation.org/event/gothamfest/

Uploaded 10-10-19

]]> 3418 no Uploaded 12-10-26 Sat, 07 Nov 2026 08:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 685 no More details: https://www.simonsfoundation.org/event/gothamfest/Uploaded 10-10-19 Sat, 07 Nov 2026 07:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/gothamfest/Uploaded 10-10-19 More details: https://www.simonsfoundation.org/event/gothamfest/

Uploaded 10-10-19

]]> 2796 no Uploaded 12-10-26 Sat, 07 Nov 2026 06:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 987 no More details: https://www.simonsfoundation.org/event/class-song-workshop/Uploaded 30-08-19 Sat, 07 Nov 2026 05:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/class-song-workshop/Uploaded 30-08-19 More details: https://www.simonsfoundation.org/event/class-song-workshop/

Uploaded 30-08-19

]]> 4034 no More details: https://www.simonsfoundation.org/event/gothamfest/Uploaded 10-10-19 Sat, 07 Nov 2026 05:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/gothamfest/Uploaded 10-10-19 More details: https://www.simonsfoundation.org/event/gothamfest/

Uploaded 10-10-19

]]> 3406 no Uploaded 12-10-26 Sat, 07 Nov 2026 04:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 779 no Jörn Venderbos: Many-body band inversionsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Sat, 07 Nov 2026 03:00:00 -0000 full Simons Foundation Jörn Venderbos: Many-body band inversionsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Jörn Venderbos: Many-body band inversions
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2236 no Uploaded 12-10-26 Sat, 07 Nov 2026 02:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 816 no Phillip Moll: Topological metals: Dirac Fermion transport in the presence of large Fermi surfacesMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Sat, 07 Nov 2026 01:00:00 -0000 full Simons Foundation Phillip Moll: Topological metals: Dirac Fermion transport in the presence of large Fermi surfacesMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Phillip Moll: Topological metals: Dirac Fermion transport in the presence of large Fermi surfaces
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2471 no Between Figures and SymbolsUploaded 07-10-26 Sat, 07 Nov 2026 00:00:00 -0000 full Simons Foundation Between Figures and SymbolsUploaded 07-10-26 Between Figures and Symbols

Uploaded 07-10-26

]]> 2503 no Uploaded 12-10-26 Sat, 07 Nov 2026 00:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 586 no Adolfo Grushin: Quantization in chiral higher-order topological insulatorsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 23:00:00 -0000 full Simons Foundation Adolfo Grushin: Quantization in chiral higher-order topological insulatorsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Adolfo Grushin: Quantization in chiral higher-order topological insulators
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2507 no Ben Wieder: Higher-Order Topology in Conventional Dirac SemimetalsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 23:00:00 -0000 full Simons Foundation Ben Wieder: Higher-Order Topology in Conventional Dirac SemimetalsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Ben Wieder: Higher-Order Topology in Conventional Dirac Semimetals
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2388 no Higher Property T, Banach Representations and ApplicationsProperty T is a group property that could be phrased by means of cohomological vanishing in degree 1 and unitary coefficients. Higher property T is the higher degree analogue. It is related to various analytic, topological and geometrical rigidity phenomena. Prominent examples of groups with higher property T are lattices in simple Lie groups. Recently, several open conjectures were proven using higher property T and some of its variants. I will survey the topic, following my joint work with Roman Sauer and my joint work with Saar Bader, Shaked Bader and Roman Sauer.Uploaded 05-10-26 Fri, 06 Nov 2026 22:51:00 -0000 full Simons Foundation Higher Property T, Banach Representations and ApplicationsProperty T is a group property that could be phrased by means of cohomological vanishing in degree 1 and unitary coefficients. Higher property T is the higher degree analogue. It is related to various analytic, topological and geometrical rigidity phenomena. Prominent examples of groups with higher property T are lattices in simple Lie groups. Recently, several open conjectures were proven using higher property T and some of its variants. I will survey the topic, following my joint work with Roman Sauer and my joint work with Saar Bader, Shaked Bader and Roman Sauer.Uploaded 05-10-26 Higher Property T, Banach Representations and Applications

Property T is a group property that could be phrased by means of cohomological vanishing in degree 1 and unitary coefficients. Higher property T is the higher degree analogue. It is related to various analytic, topological and geometrical rigidity phenomena. Prominent examples of groups with higher property T are lattices in simple Lie groups. Recently, several open conjectures were proven using higher property T and some of its variants. I will survey the topic, following my joint work with Roman Sauer and my joint work with Saar Bader, Shaked Bader and Roman Sauer.

Uploaded 05-10-26

]]> 2711 no Probabilistic Combinatorics at Exponentially Small ScalesIn many applications of the probabilistic method, one looks to study phenomena that occur "with high probability". More recently however, in an attempt to understand some of the most fundamental problems in combinatorics, researchers have been diving deeper into these probability spaces and understanding phenomena that occur at much smaller probability scales. Here I will survey a few of these ideas from the perspective of my own work in the area.Uploaded 07-10-26 Fri, 06 Nov 2026 22:00:00 -0000 full Simons Foundation Probabilistic Combinatorics at Exponentially Small ScalesIn many applications of the probabilistic method, one looks to study phenomena that occur "with high probability". More recently however, in an attempt to understand some of the most fundamental problems in combinatorics, researchers have been diving deeper into these probability spaces and understanding phenomena that occur at much smaller probability scales. Here I will survey a few of these ideas from the perspective of my own work in the area.Uploaded 07-10-26 Probabilistic Combinatorics at Exponentially Small Scales

In many applications of the probabilistic method, one looks to study phenomena that occur "with high probability". More recently however, in an attempt to understand some of the most fundamental problems in combinatorics, researchers have been diving deeper into these probability spaces and understanding phenomena that occur at much smaller probability scales. Here I will survey a few of these ideas from the perspective of my own work in the area.

Uploaded 07-10-26

]]> 2595 no Uploaded 12-10-26 Fri, 06 Nov 2026 22:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 780 no Eslam Khalaf: Shift Insulators – A simple model of fragile topologyMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 21:00:00 -0000 full Simons Foundation Eslam Khalaf: Shift Insulators – A simple model of fragile topologyMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Eslam Khalaf: Shift Insulators – A simple model of fragile topology
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2765 no Adrian Po: Symmetry indicators beyond time-reversal insulatorsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 21:00:00 -0000 full Simons Foundation Adrian Po: Symmetry indicators beyond time-reversal insulatorsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Adrian Po: Symmetry indicators beyond time-reversal insulators
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2646 no Manifolds and Disc-PresheavesIn this talk we explain an approach to the study of smooth manifolds which compares them to presheaves on a category of discs, also known as embedding calculus. We highlight recent work that shows this approach has many desirable properties, as well as recent applications demonstrating its strengthUploaded 07-10-26 Fri, 06 Nov 2026 20:00:00 -0000 full Simons Foundation Manifolds and Disc-PresheavesIn this talk we explain an approach to the study of smooth manifolds which compares them to presheaves on a category of discs, also known as embedding calculus. We highlight recent work that shows this approach has many desirable properties, as well as recent applications demonstrating its strengthUploaded 07-10-26 Manifolds and Disc-Presheaves

In this talk we explain an approach to the study of smooth manifolds which compares them to presheaves on a category of discs, also known as embedding calculus. We highlight recent work that shows this approach has many desirable properties, as well as recent applications demonstrating its strength

Uploaded 07-10-26

]]> 3053 no Uploaded 12-10-26 Fri, 06 Nov 2026 20:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 599 no Seunghun Lee: Perfect Andreev reflection due to Klein paradox in a topological superconducting stateMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 19:00:00 -0000 full Simons Foundation Seunghun Lee: Perfect Andreev reflection due to Klein paradox in a topological superconducting stateMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Seunghun Lee: Perfect Andreev reflection due to Klein paradox in a topological superconducting state
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 1762 no Mallika Randeria: Imaging nematic quantum Hall states and their interacting boundary modesMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 19:00:00 -0000 full Simons Foundation Mallika Randeria: Imaging nematic quantum Hall states and their interacting boundary modesMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Mallika Randeria: Imaging nematic quantum Hall states and their interacting boundary modes
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2541 no Uploaded 12-10-26 Fri, 06 Nov 2026 18:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 616 no The Mean-Field Dynamics of TransformersWe develop a mathematical framework that interprets Transformer attention as an interacting particle system and studies its continuum (mean-field) limits. By idealizing attention on the sphere, we connect Transformer dynamics to Wasserstein gradient flows, synchronization models (Kuramoto), and mean-shift clustering. Central to our results is a global clustering phenomenon whereby tokens cluster asymptotically after long metastable states where they are arranged into multiple clusters. We further analyze a tractable equiangular reduction to obtain exact clustering rates, show how commonly used normalization schemes alter contraction speeds, and identify a phase transition for long-context attention. The results highlight both the mechanisms that drive representation collapse and the regimes that preserve expressive, multi-cluster structure in deep attention architectures.Uploaded 06-10-26 Fri, 06 Nov 2026 18:00:00 -0000 full Simons Foundation The Mean-Field Dynamics of TransformersWe develop a mathematical framework that interprets Transformer attention as an interacting particle system and studies its continuum (mean-field) limits. By idealizing attention on the sphere, we connect Transformer dynamics to Wasserstein gradient flows, synchronization models (Kuramoto), and mean-shift clustering. Central to our results is a global clustering phenomenon whereby tokens cluster asymptotically after long metastable states where they are arranged into multiple clusters. We further analyze a tractable equiangular reduction to obtain exact clustering rates, show how commonly used normalization schemes alter contraction speeds, and identify a phase transition for long-context attention. The results highlight both the mechanisms that drive representation collapse and the regimes that preserve expressive, multi-cluster structure in deep attention architectures.Uploaded 06-10-26 The Mean-Field Dynamics of Transformers

We develop a mathematical framework that interprets Transformer attention as an interacting particle system and studies its continuum (mean-field) limits. By idealizing attention on the sphere, we connect Transformer dynamics to Wasserstein gradient flows, synchronization models (Kuramoto), and mean-shift clustering. Central to our results is a global clustering phenomenon whereby tokens cluster asymptotically after long metastable states where they are arranged into multiple clusters. We further analyze a tractable equiangular reduction to obtain exact clustering rates, show how commonly used normalization schemes alter contraction speeds, and identify a phase transition for long-context attention. The results highlight both the mechanisms that drive representation collapse and the regimes that preserve expressive, multi-cluster structure in deep attention architectures.

Uploaded 06-10-26

]]> 3167 no Yi Li: Monopole Harmonic Ordering in Well Semi-metalsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 17:00:00 -0000 full Simons Foundation Yi Li: Monopole Harmonic Ordering in Well Semi-metalsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Yi Li: Monopole Harmonic Ordering in Well Semi-metals
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2671 no Barry Bradlyn: Chiral currents in a correlated insulator: Weyl-charge density wavesMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 17:00:00 -0000 full Simons Foundation Barry Bradlyn: Chiral currents in a correlated insulator: Weyl-charge density wavesMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Barry Bradlyn: Chiral currents in a correlated insulator: Weyl-charge density waves
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 3026 no Conic Optimization for Extremal GeometryThe aim of this lecture is to highlight recent progress in using conic optimization methods to study geometric packing problems. We will look at four geometric packing problems of different kinds: two on the unit sphere-the kissing number problem and measurable \pi/2-avoiding sets-and two in Euclidean space---the sphere packing problem and measurable one-avoiding sets.Uploaded 06-10-26 Fri, 06 Nov 2026 16:00:00 -0000 full Simons Foundation Conic Optimization for Extremal GeometryThe aim of this lecture is to highlight recent progress in using conic optimization methods to study geometric packing problems. We will look at four geometric packing problems of different kinds: two on the unit sphere-the kissing number problem and measurable \pi/2-avoiding sets-and two in Euclidean space---the sphere packing problem and measurable one-avoiding sets.Uploaded 06-10-26 Conic Optimization for Extremal Geometry

The aim of this lecture is to highlight recent progress in using conic optimization methods to study geometric packing problems. We will look at four geometric packing problems of different kinds: two on the unit sphere-the kissing number problem and measurable \pi/2-avoiding sets-and two in Euclidean space---the sphere packing problem and measurable one-avoiding sets.

Uploaded 06-10-26

]]> 2879 no Uploaded 12-10-26 Fri, 06 Nov 2026 16:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 585 no More details: https://www.simonsfoundation.org/event/class-song-workshop/Uploaded 30-08-19 Fri, 06 Nov 2026 15:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/class-song-workshop/Uploaded 30-08-19 More details: https://www.simonsfoundation.org/event/class-song-workshop/

Uploaded 30-08-19

]]> 4000 no Binghai Yan: New insights for magnetic topological materialsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 15:00:00 -0000 full Simons Foundation Binghai Yan: New insights for magnetic topological materialsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Binghai Yan: New insights for magnetic topological materials
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2427 no Kaustuv Manna: Discovery of multifold fermions and observation of quantized Photocurrents in topological chiral crystalsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 15:00:00 -0000 full Simons Foundation Kaustuv Manna: Discovery of multifold fermions and observation of quantized Photocurrents in topological chiral crystalsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Kaustuv Manna: Discovery of multifold fermions and observation of quantized Photocurrents in topological chiral crystals
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2683 no Uploaded 12-10-26 Fri, 06 Nov 2026 14:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 632 no On Complexity of Deterministic Model Based Derivative Free Optimization MethodsIn many applications of mathematical optimization, one may wish to optimize an objective function without access to its derivatives. These situations call for derivative-free optimization (DFO) methods. Among the most successful approaches in practice are model-based trust-region methods, such as those pioneered by M.J.D Powell. While relatively complex to implement, these methods are now available in standard scientific computing platforms, including MATLAB and SciPy. However, theoretical analysis of their computational complexity lags behind practice. In particular, it is important to bound the number of function evaluations required to achieve a desired level of accuracy. In this lecture we will discuss a variety of derivative free optimization methods and their worst case complexity bounds. We will then show how to systematically derive complexity bounds for classical model based trust region methods and their modern variations. We establish, for the first time, that these methods can have the same worst case complexity than any other known DFO method. We will conclude with some of the open problems and future directions in this domain.Uploaded 06-10-26 Fri, 06 Nov 2026 14:00:00 -0000 full Simons Foundation On Complexity of Deterministic Model Based Derivative Free Optimization MethodsIn many applications of mathematical optimization, one may wish to optimize an objective function without access to its derivatives. These situations call for derivative-free optimization (DFO) methods. Among the most successful approaches in practice are model-based trust-region methods, such as those pioneered by M.J.D Powell. While relatively complex to implement, these methods are now available in standard scientific computing platforms, including MATLAB and SciPy. However, theoretical analysis of their computational complexity lags behind practice. In particular, it is important to bound the number of function evaluations required to achieve a desired level of accuracy. In this lecture we will discuss a variety of derivative free optimization methods and their worst case complexity bounds. We will then show how to systematically derive complexity bounds for classical model based trust region methods and their modern variations. We establish, for the first time, that these methods can have the same worst case complexity than any other known DFO method. We will conclude with some of the open problems and future directions in this domain.Uploaded 06-10-26 On Complexity of Deterministic Model Based Derivative Free Optimization Methods

In many applications of mathematical optimization, one may wish to optimize an objective function without access to its derivatives. These situations call for derivative-free optimization (DFO) methods. Among the most successful approaches in practice are model-based trust-region methods, such as those pioneered by M.J.D Powell. While relatively complex to implement, these methods are now available in standard scientific computing platforms, including MATLAB and SciPy. However, theoretical analysis of their computational complexity lags behind practice. In particular, it is important to bound the number of function evaluations required to achieve a desired level of accuracy. In this lecture we will discuss a variety of derivative free optimization methods and their worst case complexity bounds. We will then show how to systematically derive complexity bounds for classical model based trust region methods and their modern variations. We establish, for the first time, that these methods can have the same worst case complexity than any other known DFO method. We will conclude with some of the open problems and future directions in this domain.

Uploaded 06-10-26

]]> 2800 no Fernando de Juan: Intrinsic circular photocurrents in topological semimetalsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 13:00:00 -0000 full Simons Foundation Fernando de Juan: Intrinsic circular photocurrents in topological semimetalsMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fernando de Juan: Intrinsic circular photocurrents in topological semimetals
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2534 no Berthold Jaeck: Observation of a Majorana zero mode in a topologically protected edge channelMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 13:00:00 -0000 full Simons Foundation Berthold Jaeck: Observation of a Majorana zero mode in a topologically protected edge channelMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Berthold Jaeck: Observation of a Majorana zero mode in a topologically protected edge channel
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2534 no Uploaded 12-10-26 Fri, 06 Nov 2026 12:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 1158 no From Stein Manifolds to Oka Manifolds: The H-Principle in Complex AnalysisIn this talk, I will describe the main developments in the theory of the h-principle in complex analysis and geometry, better known as the Oka principle. I will present the key notions of Oka manifolds and Oka maps, which developed from the Oka-Grauert principle and Gromov's theory of elliptic complex manifolds and elliptic holomorphic submersions, and their characterization by simpler approximation and ellipticity conditions. I will discuss recent and ongoing developments, open problems, and mention applications to the classical theory of minimal surfaces.Uploaded 06-10-26 Fri, 06 Nov 2026 12:00:00 -0000 full Simons Foundation From Stein Manifolds to Oka Manifolds: The H-Principle in Complex AnalysisIn this talk, I will describe the main developments in the theory of the h-principle in complex analysis and geometry, better known as the Oka principle. I will present the key notions of Oka manifolds and Oka maps, which developed from the Oka-Grauert principle and Gromov's theory of elliptic complex manifolds and elliptic holomorphic submersions, and their characterization by simpler approximation and ellipticity conditions. I will discuss recent and ongoing developments, open problems, and mention applications to the classical theory of minimal surfaces.Uploaded 06-10-26 From Stein Manifolds to Oka Manifolds: The H-Principle in Complex Analysis

In this talk, I will describe the main developments in the theory of the h-principle in complex analysis and geometry, better known as the Oka principle. I will present the key notions of Oka manifolds and Oka maps, which developed from the Oka-Grauert principle and Gromov's theory of elliptic complex manifolds and elliptic holomorphic submersions, and their characterization by simpler approximation and ellipticity conditions. I will discuss recent and ongoing developments, open problems, and mention applications to the classical theory of minimal surfaces.

Uploaded 06-10-26

]]> 2947 no Jiun-Haw Chu: Strain-tuned topological and quantum phase transitionMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 11:00:00 -0000 full Simons Foundation Jiun-Haw Chu: Strain-tuned topological and quantum phase transitionMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Jiun-Haw Chu: Strain-tuned topological and quantum phase transition
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2303 no More details: https://www.simonsfoundation.org/event/ccb-colloquium-chao-tang/Uploaded 14-10-19 Fri, 06 Nov 2026 11:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/ccb-colloquium-chao-tang/Uploaded 14-10-19 More details: https://www.simonsfoundation.org/event/ccb-colloquium-chao-tang/

Uploaded 14-10-19

]]> 4455 no Uploaded 12-10-26 Fri, 06 Nov 2026 10:00:00 -0000 full Simons Foundation Uploaded 12-10-26 Uploaded 12-10-26

]]> 996 no Holomorphic Foliations with Numerically Trivial Canonical BundleThe lecture will survey what is currently known about the structure of holomorphic foliations with canonical singularlities and numerically trivial canonical bundle on projective manifolds.Uploaded 06-10-26 Fri, 06 Nov 2026 10:00:00 -0000 full Simons Foundation Holomorphic Foliations with Numerically Trivial Canonical BundleThe lecture will survey what is currently known about the structure of holomorphic foliations with canonical singularlities and numerically trivial canonical bundle on projective manifolds.Uploaded 06-10-26 Holomorphic Foliations with Numerically Trivial Canonical Bundle

The lecture will survey what is currently known about the structure of holomorphic foliations with canonical singularlities and numerically trivial canonical bundle on projective manifolds.

Uploaded 06-10-26

]]> 2842 no Kin Fai Mak: Nonlinear anomalous Hall effectMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 09:00:00 -0000 full Simons Foundation Kin Fai Mak: Nonlinear anomalous Hall effectMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Kin Fai Mak: Nonlinear anomalous Hall effect
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2250 no Progress has transformed natural wildernesses into artificial landscapes, swapping forests and meadows for farms and megamalls. Nearly 20 years ago, Isabella Tree and her husband Charlie Burrell set out to bring the wild back to their 3,500-acre farm in southeastern England. Over the years, a long-lost ecosystem reemerged, including the return of rare wildlife species such as turtle doves and nightingales.Uploaded 16-10-19Tree will recount the challenges and successes of this experiment, which she chronicles in her new book “Wilding: Returning Nature to Our Farm.” She hopes that their farm will serve as a blueprint for ecological restoration.More details: https://www.simonsfoundation.org/event/isabella-tree-and-rewilding-an-english-farm/https://www.simonsfoundation.org/event/isabella-tree-and-rewilding-an-english-farm/ Fri, 06 Nov 2026 09:00:00 -0000 full Simons Foundation Progress has transformed natural wildernesses into artificial landscapes, swapping forests and meadows for farms and megamalls. Nearly 20 years ago, Isabella Tree and her husband Charlie Burrell set out to bring the wild back to their 3,500-acre farm in southeastern England. Over the years, a long-lost ecosystem reemerged, including the return of rare wildlife species such as turtle doves and nightingales.Uploaded 16-10-19Tree will recount the challenges and successes of this experiment, which she chronicles in her new book “Wilding: Returning Nature to Our Farm.” She hopes that their farm will serve as a blueprint for ecological restoration.More details: https://www.simonsfoundation.org/event/isabella-tree-and-rewilding-an-english-farm/https://www.simonsfoundation.org/event/isabella-tree-and-rewilding-an-english-farm/ Progress has transformed natural wildernesses into artificial landscapes, swapping forests and meadows for farms and megamalls. Nearly 20 years ago, Isabella Tree and her husband Charlie Burrell set out to bring the wild back to their 3,500-acre farm in southeastern England. Over the years, a long-lost ecosystem reemerged, including the return of rare wildlife species such as turtle doves and nightingales.

Uploaded 16-10-19

Tree will recount the challenges and successes of this experiment, which she chronicles in her new book “Wilding: Returning Nature to Our Farm.” She hopes that their farm will serve as a blueprint for ecological restoration.
More details: https://www.simonsfoundation.org/event/isabella-tree-and-rewilding-an-english-farm/https://www.simonsfoundation.org/event/isabella-tree-and-rewilding-an-english-farm/

]]> 3420 no Classical Control of a Quantum SystemIn this talk, we'll discuss the connection between the problem of learning with errors (LWE) and quantum computation. LWE is a widely studied cryptographic assumption which is believed to be secure even for quantum computers, unlike assumptions that are commonly used today. We'll discuss how, even though LWE does not seem to have enough structure to be amenable to quantum algorithms, it does have enough structure to enable uniquely quantum functionality. We'll illustrate this by describing how the LWE assumption can be used to classically control a quantum system.Uploaded 05-10-26 Fri, 06 Nov 2026 08:51:00 -0000 full Simons Foundation Classical Control of a Quantum SystemIn this talk, we'll discuss the connection between the problem of learning with errors (LWE) and quantum computation. LWE is a widely studied cryptographic assumption which is believed to be secure even for quantum computers, unlike assumptions that are commonly used today. We'll discuss how, even though LWE does not seem to have enough structure to be amenable to quantum algorithms, it does have enough structure to enable uniquely quantum functionality. We'll illustrate this by describing how the LWE assumption can be used to classically control a quantum system.Uploaded 05-10-26 Classical Control of a Quantum System

In this talk, we'll discuss the connection between the problem of learning with errors (LWE) and quantum computation. LWE is a widely studied cryptographic assumption which is believed to be secure even for quantum computers, unlike assumptions that are commonly used today. We'll discuss how, even though LWE does not seem to have enough structure to be amenable to quantum algorithms, it does have enough structure to enable uniquely quantum functionality. We'll illustrate this by describing how the LWE assumption can be used to classically control a quantum system.

Uploaded 05-10-26

]]> 3079 no The Geometry of Spherical Spin GlassesSpherical spin glasses are random energy functions on the sphere in high-dimensional Euclidean space, originally introduced in physics as theoretical models for disordered magnetic materials. I will present geometric descriptions of their Gibbs measures that relate their asymptotic support to structural features of the energy landscape (such as bands around critical points or approximate maximizers at certain special radii). I will briefly mention how these geometric descriptions relate to and complement the Parisi theory and how they are used both to make rigorous and to generalize certain predictions from the Thouless-Anderson-Palmer approach. Finally, I will explain how these geometric results recently led to optimization algorithms and algorithms for solving random polynomial systems that are provably optimal within a natural class of stable algorithms.Uploaded 07-10-26 Fri, 06 Nov 2026 08:00:00 -0000 full Simons Foundation The Geometry of Spherical Spin GlassesSpherical spin glasses are random energy functions on the sphere in high-dimensional Euclidean space, originally introduced in physics as theoretical models for disordered magnetic materials. I will present geometric descriptions of their Gibbs measures that relate their asymptotic support to structural features of the energy landscape (such as bands around critical points or approximate maximizers at certain special radii). I will briefly mention how these geometric descriptions relate to and complement the Parisi theory and how they are used both to make rigorous and to generalize certain predictions from the Thouless-Anderson-Palmer approach. Finally, I will explain how these geometric results recently led to optimization algorithms and algorithms for solving random polynomial systems that are provably optimal within a natural class of stable algorithms.Uploaded 07-10-26 The Geometry of Spherical Spin Glasses

Spherical spin glasses are random energy functions on the sphere in high-dimensional Euclidean space, originally introduced in physics as theoretical models for disordered magnetic materials. I will present geometric descriptions of their Gibbs measures that relate their asymptotic support to structural features of the energy landscape (such as bands around critical points or approximate maximizers at certain special radii). I will briefly mention how these geometric descriptions relate to and complement the Parisi theory and how they are used both to make rigorous and to generalize certain predictions from the Thouless-Anderson-Palmer approach. Finally, I will explain how these geometric results recently led to optimization algorithms and algorithms for solving random polynomial systems that are provably optimal within a natural class of stable algorithms.

Uploaded 07-10-26

]]> 2784 no Universality for Two Dimensional Kinetically Constrained Spin ModelsKinetically constrained models (KCMs) are interacting particle systems introduced in the '80s by condensed matter physicists. These models provide accessible stochastic systems with glassy-type dynamics. The key mechanism behind their complex evolution is dynamical facilitation, embedded via appropriate kinetic constraints. KCMs are tightly related to bootstrap percolation, a widely studied monotone cellular automaton. Recently, KCMs have inspired the construction of quantum spin chains to explore many-body localization in the absence of disorder. I will begin with a short review of KCMs' main features and the behavior of two popular models. Then, I will focus on the KCMs counterpart of the famous “universality problem” for two-dimensional bootstrap percolation. In particular, I will highlight the major new features that emerge for KCMs with respect to bootstrap percolation.Uploaded 06-10-26 Fri, 06 Nov 2026 08:00:00 -0000 full Simons Foundation Universality for Two Dimensional Kinetically Constrained Spin ModelsKinetically constrained models (KCMs) are interacting particle systems introduced in the '80s by condensed matter physicists. These models provide accessible stochastic systems with glassy-type dynamics. The key mechanism behind their complex evolution is dynamical facilitation, embedded via appropriate kinetic constraints. KCMs are tightly related to bootstrap percolation, a widely studied monotone cellular automaton. Recently, KCMs have inspired the construction of quantum spin chains to explore many-body localization in the absence of disorder. I will begin with a short review of KCMs' main features and the behavior of two popular models. Then, I will focus on the KCMs counterpart of the famous “universality problem” for two-dimensional bootstrap percolation. In particular, I will highlight the major new features that emerge for KCMs with respect to bootstrap percolation.Uploaded 06-10-26 Universality for Two Dimensional Kinetically Constrained Spin Models

Kinetically constrained models (KCMs) are interacting particle systems introduced in the '80s by condensed matter physicists. These models provide accessible stochastic systems with glassy-type dynamics. The key mechanism behind their complex evolution is dynamical facilitation, embedded via appropriate kinetic constraints. KCMs are tightly related to bootstrap percolation, a widely studied monotone cellular automaton. Recently, KCMs have inspired the construction of quantum spin chains to explore many-body localization in the absence of disorder. I will begin with a short review of KCMs' main features and the behavior of two popular models. Then, I will focus on the KCMs counterpart of the famous “universality problem” for two-dimensional bootstrap percolation. In particular, I will highlight the major new features that emerge for KCMs with respect to bootstrap percolation.

Uploaded 06-10-26

]]> 2915 no The differences between the sexes extend down to our cells. Biomedical research and medical teaching and practice, however, often overlook the ways male and female cells, tissues and organs differ.Uploaded 18-10-19In this lecture, David Page will discuss recent advances in his lab that provide a framework for studying sex differences at the molecular level. His lab conducted a five-species, twelve-tissue survey of sex differences in gene expression, creating the first comprehensive catalog of molecular-level differences between males and females across the body. The study included humans as well as four species used as models in basic, clinical, and pharmaceutical research. Page’s lab identified many genes that were sex-biased in their expression (i.e., expressed more abundantly in males than females, or vice versa) in a variety of tissues. Some of this sex-biased gene expression is conserved across mammalian species. Using this unprecedented dataset, they discovered a link between conserved sex-biased gene expression and a prominent phenotypic sex difference found in most mammalian species: an upward shift in the distribution of height or body size in males compared to females.More details: https://www.simonsfoundation.org/event/sex-differences-in-health-and-disease-do-males-and-females-read-their-genomes-differently/ Fri, 06 Nov 2026 07:00:00 -0000 full Simons Foundation The differences between the sexes extend down to our cells. Biomedical research and medical teaching and practice, however, often overlook the ways male and female cells, tissues and organs differ.Uploaded 18-10-19In this lecture, David Page will discuss recent advances in his lab that provide a framework for studying sex differences at the molecular level. His lab conducted a five-species, twelve-tissue survey of sex differences in gene expression, creating the first comprehensive catalog of molecular-level differences between males and females across the body. The study included humans as well as four species used as models in basic, clinical, and pharmaceutical research. Page’s lab identified many genes that were sex-biased in their expression (i.e., expressed more abundantly in males than females, or vice versa) in a variety of tissues. Some of this sex-biased gene expression is conserved across mammalian species. Using this unprecedented dataset, they discovered a link between conserved sex-biased gene expression and a prominent phenotypic sex difference found in most mammalian species: an upward shift in the distribution of height or body size in males compared to females.More details: https://www.simonsfoundation.org/event/sex-differences-in-health-and-disease-do-males-and-females-read-their-genomes-differently/ The differences between the sexes extend down to our cells. Biomedical research and medical teaching and practice, however, often overlook the ways male and female cells, tissues and organs differ.

Uploaded 18-10-19

In this lecture, David Page will discuss recent advances in his lab that provide a framework for studying sex differences at the molecular level. His lab conducted a five-species, twelve-tissue survey of sex differences in gene expression, creating the first comprehensive catalog of molecular-level differences between males and females across the body. The study included humans as well as four species used as models in basic, clinical, and pharmaceutical research. Page’s lab identified many genes that were sex-biased in their expression (i.e., expressed more abundantly in males than females, or vice versa) in a variety of tissues. Some of this sex-biased gene expression is conserved across mammalian species. Using this unprecedented dataset, they discovered a link between conserved sex-biased gene expression and a prominent phenotypic sex difference found in most mammalian species: an upward shift in the distribution of height or body size in males compared to females.
More details: https://www.simonsfoundation.org/event/sex-differences-in-health-and-disease-do-males-and-females-read-their-genomes-differently/

]]> 3481 no Inti Sodemann: The Non-linear Hall effect and Quantum Rectification Sum RuleMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 07:00:00 -0000 full Simons Foundation Inti Sodemann: The Non-linear Hall effect and Quantum Rectification Sum RuleMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Inti Sodemann: The Non-linear Hall effect and Quantum Rectification Sum Rule
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2518 no Symplectic Weyl LawsWe survey a number of formulas that have recently been established in low-dimensional symplectic geometry that are analogous to Weyl's Law for the Laplace spectrum. We discuss applications to problems in dynamics and problems about the algebraic structure of certain groups of homeomorphisms of surfaces. We state some open questions related to the subleading asymptotics.Uploaded 06-10-26 Fri, 06 Nov 2026 06:00:00 -0000 full Simons Foundation Symplectic Weyl LawsWe survey a number of formulas that have recently been established in low-dimensional symplectic geometry that are analogous to Weyl's Law for the Laplace spectrum. We discuss applications to problems in dynamics and problems about the algebraic structure of certain groups of homeomorphisms of surfaces. We state some open questions related to the subleading asymptotics.Uploaded 06-10-26 Symplectic Weyl Laws

We survey a number of formulas that have recently been established in low-dimensional symplectic geometry that are analogous to Weyl's Law for the Laplace spectrum. We discuss applications to problems in dynamics and problems about the algebraic structure of certain groups of homeomorphisms of surfaces. We state some open questions related to the subleading asymptotics.

Uploaded 06-10-26

]]> 2701 no Synthetic Perspectives on Higher StructuresThrough painstaking work, higher structures, such as weak infinite-dimensional categories, can be built "analytically" out of sets. Elaborate formalisms have been developed to ensure that constructions involving these objects are equivalence-invariant. We present an alternate approach using domain-specific formal languages to work with higher structures "synthetically." We argue such formal systems make definitions, theorems, and proofs both easier to understand and easier to formalize. Our contributions to the synthetic theory of higher categories were developed over the course of joint work with Dominic Verity, Mike Shulman, Evan Cavallo, and Christian Sattler, among others.Uploaded 07-10-26 Fri, 06 Nov 2026 06:00:00 -0000 full Simons Foundation Synthetic Perspectives on Higher StructuresThrough painstaking work, higher structures, such as weak infinite-dimensional categories, can be built "analytically" out of sets. Elaborate formalisms have been developed to ensure that constructions involving these objects are equivalence-invariant. We present an alternate approach using domain-specific formal languages to work with higher structures "synthetically." We argue such formal systems make definitions, theorems, and proofs both easier to understand and easier to formalize. Our contributions to the synthetic theory of higher categories were developed over the course of joint work with Dominic Verity, Mike Shulman, Evan Cavallo, and Christian Sattler, among others.Uploaded 07-10-26 Synthetic Perspectives on Higher Structures

Through painstaking work, higher structures, such as weak infinite-dimensional categories, can be built "analytically" out of sets. Elaborate formalisms have been developed to ensure that constructions involving these objects are equivalence-invariant. We present an alternate approach using domain-specific formal languages to work with higher structures "synthetically." We argue such formal systems make definitions, theorems, and proofs both easier to understand and easier to formalize. Our contributions to the synthetic theory of higher categories were developed over the course of joint work with Dominic Verity, Mike Shulman, Evan Cavallo, and Christian Sattler, among others.

Uploaded 07-10-26

]]> 2980 no I will review how massive black holes may have formed in the earlyuniverse from stellar-mass black hole remnants, via super-Eddingtonaccretion, or run-away mergers of stellar-mass objects. I will thendiscuss the role of circumbinary gas in mergers of black holes: forfacilitating (or not) the early inspiral, producing uniqueelectromagnetic signatures, and impacting low-frequency gravitationalwaves.More details: https://www.simonsfoundation.org/event/cca-colloquium-zoltan-haiman/Uploaded 23-10-19 Fri, 06 Nov 2026 05:00:00 -0000 full Simons Foundation I will review how massive black holes may have formed in the earlyuniverse from stellar-mass black hole remnants, via super-Eddingtonaccretion, or run-away mergers of stellar-mass objects. I will thendiscuss the role of circumbinary gas in mergers of black holes: forfacilitating (or not) the early inspiral, producing uniqueelectromagnetic signatures, and impacting low-frequency gravitationalwaves.More details: https://www.simonsfoundation.org/event/cca-colloquium-zoltan-haiman/Uploaded 23-10-19 I will review how massive black holes may have formed in the early
universe from stellar-mass black hole remnants, via super-Eddington
accretion, or run-away mergers of stellar-mass objects. I will then
discuss the role of circumbinary gas in mergers of black holes: for
facilitating (or not) the early inspiral, producing unique
electromagnetic signatures, and impacting low-frequency gravitational
waves.
More details: https://www.simonsfoundation.org/event/cca-colloquium-zoltan-haiman/

Uploaded 23-10-19

]]> 4171 no Leslie Schoop: Chemical bonds in square nets and their relation to topologyMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 05:00:00 -0000 full Simons Foundation Leslie Schoop: Chemical bonds in square nets and their relation to topologyMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Leslie Schoop: Chemical bonds in square nets and their relation to topology
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2145 no The Lens of Abelian EmbeddingsWe discuss a recent line of research investigating inverse theorems with respect to general k-wise correlations, and explain how such correlations arise in different contexts in mathematics. We outline some of the results that were established and their applications in discrete mathematics and theoretical computer science.Uploaded 06-10-26 Fri, 06 Nov 2026 04:00:00 -0000 full Simons Foundation The Lens of Abelian EmbeddingsWe discuss a recent line of research investigating inverse theorems with respect to general k-wise correlations, and explain how such correlations arise in different contexts in mathematics. We outline some of the results that were established and their applications in discrete mathematics and theoretical computer science.Uploaded 06-10-26 The Lens of Abelian Embeddings

We discuss a recent line of research investigating inverse theorems with respect to general k-wise correlations, and explain how such correlations arise in different contexts in mathematics. We outline some of the results that were established and their applications in discrete mathematics and theoretical computer science.

Uploaded 06-10-26

]]> 2871 no Control of Some Coupled Pde Systems of Mixed TypesThe initial part of the talk reviews some results on control and stabilization of some coupled PDE systems of mixed types, obtained with our collaborators. The latter part is specifically on new results with our collaborators, on stabilization or the lack of, for these systems. An outline of the proof for both positive and negative results will be indicated. These do not use the full knowledge of the spectrum. The negative result relies on a construction of highly localized solutions using certain ansatz involving complex exponentials and hence works for such coupled systems with variable coefficients and lower order terms.Uploaded 07-10-26 Fri, 06 Nov 2026 04:00:00 -0000 full Simons Foundation Control of Some Coupled Pde Systems of Mixed TypesThe initial part of the talk reviews some results on control and stabilization of some coupled PDE systems of mixed types, obtained with our collaborators. The latter part is specifically on new results with our collaborators, on stabilization or the lack of, for these systems. An outline of the proof for both positive and negative results will be indicated. These do not use the full knowledge of the spectrum. The negative result relies on a construction of highly localized solutions using certain ansatz involving complex exponentials and hence works for such coupled systems with variable coefficients and lower order terms.Uploaded 07-10-26 Control of Some Coupled Pde Systems of Mixed Types

The initial part of the talk reviews some results on control and stabilization of some coupled PDE systems of mixed types, obtained with our collaborators. The latter part is specifically on new results with our collaborators, on stabilization or the lack of, for these systems. An outline of the proof for both positive and negative results will be indicated. These do not use the full knowledge of the spectrum. The negative result relies on a construction of highly localized solutions using certain ansatz involving complex exponentials and hence works for such coupled systems with variable coefficients and lower order terms.

Uploaded 07-10-26

]]> 2826 no Line intensity mapping (LIM), in which line emission from unresolved galaxies is mapped onto a 3D field, has emerged as a unique probe of the gas content and star formation history of the Universe as well as large-scale structure across cosmic time. In this talk, I will present the science potential of LIM as well as surveys which will provide the data for these analyses. After a brief introduction to LIM, I will introduce the [CII] emission line and explain what mapping this line can teach us about star formation and the interstellar medium, after which I’ll present recent measurements we performed of the diffuse [CII] intensity. Next, I will describe the LIM survey EXCLAIM, a NASA mission which will map CO and [CII] emission to probe star formation and the ISM over cosmic time. Finally, I will present SPHEREx, another upcoming NASA mission which will characterize cosmic inflation as well as the ISM.More details: https://www.simonsfoundation.org/event/cca-colloquium-anthony-pullen/Uploaded 23-10-19 Fri, 06 Nov 2026 03:00:00 -0000 full Simons Foundation Line intensity mapping (LIM), in which line emission from unresolved galaxies is mapped onto a 3D field, has emerged as a unique probe of the gas content and star formation history of the Universe as well as large-scale structure across cosmic time. In this talk, I will present the science potential of LIM as well as surveys which will provide the data for these analyses. After a brief introduction to LIM, I will introduce the [CII] emission line and explain what mapping this line can teach us about star formation and the interstellar medium, after which I’ll present recent measurements we performed of the diffuse [CII] intensity. Next, I will describe the LIM survey EXCLAIM, a NASA mission which will map CO and [CII] emission to probe star formation and the ISM over cosmic time. Finally, I will present SPHEREx, another upcoming NASA mission which will characterize cosmic inflation as well as the ISM.More details: https://www.simonsfoundation.org/event/cca-colloquium-anthony-pullen/Uploaded 23-10-19 Line intensity mapping (LIM), in which line emission from unresolved galaxies is mapped onto a 3D field, has emerged as a unique probe of the gas content and star formation history of the Universe as well as large-scale structure across cosmic time. In this talk, I will present the science potential of LIM as well as surveys which will provide the data for these analyses. After a brief introduction to LIM, I will introduce the [CII] emission line and explain what mapping this line can teach us about star formation and the interstellar medium, after which I’ll present recent measurements we performed of the diffuse [CII] intensity. Next, I will describe the LIM survey EXCLAIM, a NASA mission which will map CO and [CII] emission to probe star formation and the ISM over cosmic time. Finally, I will present SPHEREx, another upcoming NASA mission which will characterize cosmic inflation as well as the ISM.
More details: https://www.simonsfoundation.org/event/cca-colloquium-anthony-pullen/

Uploaded 23-10-19

]]> 3784 no Maia Garcia Vergniory: Topological semimetals, from theoretical prediction to experimental realizationMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 03:00:00 -0000 full Simons Foundation Maia Garcia Vergniory: Topological semimetals, from theoretical prediction to experimental realizationMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Maia Garcia Vergniory: Topological semimetals, from theoretical prediction to experimental realization
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2564 no A Calabi-Yau Theorem for Degenerations of Compact Kähler ManifoldsTo understand a compact Kähler manifold X, it is often helpful to study its degenerations. The idea of non-Archimedean (n-A) Kähler geometry is to think of such degenerations as (possibly weak) Kähler potentials on an associated n-A space. The n-A Monge-Ampère measure of a degeneration is then supposed to encode how the volume of X distributes as X degenerates. In this talk I will discuss a Calabi-Yau theorem in this setting, first proved in the algebraic case by Sébastien Boucksom and Mattias Jonsson (building on earlier work of Sébastien Boucksom, Charles Favre and Mattias Jonsson), and subsequently proved in the general Kähler case by Pietro Mesquita-Piccione and myself. The proof in the Kähler case relies on properties of big cohomology classes, and is related to the transcendental Morse inequality conjecture of Sébastien Boucksom, Jean-Pierre Demailly, Mihai Păun and Thomas Peternell.Uploaded 06-10-26 Fri, 06 Nov 2026 02:00:00 -0000 full Simons Foundation A Calabi-Yau Theorem for Degenerations of Compact Kähler ManifoldsTo understand a compact Kähler manifold X, it is often helpful to study its degenerations. The idea of non-Archimedean (n-A) Kähler geometry is to think of such degenerations as (possibly weak) Kähler potentials on an associated n-A space. The n-A Monge-Ampère measure of a degeneration is then supposed to encode how the volume of X distributes as X degenerates. In this talk I will discuss a Calabi-Yau theorem in this setting, first proved in the algebraic case by Sébastien Boucksom and Mattias Jonsson (building on earlier work of Sébastien Boucksom, Charles Favre and Mattias Jonsson), and subsequently proved in the general Kähler case by Pietro Mesquita-Piccione and myself. The proof in the Kähler case relies on properties of big cohomology classes, and is related to the transcendental Morse inequality conjecture of Sébastien Boucksom, Jean-Pierre Demailly, Mihai Păun and Thomas Peternell.Uploaded 06-10-26 A Calabi-Yau Theorem for Degenerations of Compact Kähler Manifolds

To understand a compact Kähler manifold X, it is often helpful to study its degenerations. The idea of non-Archimedean (n-A) Kähler geometry is to think of such degenerations as (possibly weak) Kähler potentials on an associated n-A space. The n-A Monge-Ampère measure of a degeneration is then supposed to encode how the volume of X distributes as X degenerates. In this talk I will discuss a Calabi-Yau theorem in this setting, first proved in the algebraic case by Sébastien Boucksom and Mattias Jonsson (building on earlier work of Sébastien Boucksom, Charles Favre and Mattias Jonsson), and subsequently proved in the general Kähler case by Pietro Mesquita-Piccione and myself. The proof in the Kähler case relies on properties of big cohomology classes, and is related to the transcendental Morse inequality conjecture of Sébastien Boucksom, Jean-Pierre Demailly, Mihai Păun and Thomas Peternell.

Uploaded 06-10-26

]]> 3054 no Geometric Characteristics of Observable RegionsObservability is one of the main research areas in control theory. Different forms of observability inequalities not only correspond to different control phenomena but also have their own mathematical meanings. For evolutionary partial differential equations (PDEs), looking into the geometric characteristics of their observable sets/regions is one of the key parts in studying the corresponding observability inequalities. However, research in this area is still far from well understood. In this paper, we first present four distinct observability inequalities within the framework of abstract evolution equations, together with their corresponding control problems. Then, for several specific evolution equations (such as wave equations, heat equations, Schrödinger equations, among others), we provide the definitions of observable sets/regions corresponding to the aforementioned inequalities. Subsequently, we review some existing results and main research methods concerning the geometric characteristics of these observable sets/regions. Finally, we outline several open problems related to the geometric characteristics of observable (and weakly observable, etc.) sets/regions.Uploaded 07-10-26 Fri, 06 Nov 2026 02:00:00 -0000 full Simons Foundation Geometric Characteristics of Observable RegionsObservability is one of the main research areas in control theory. Different forms of observability inequalities not only correspond to different control phenomena but also have their own mathematical meanings. For evolutionary partial differential equations (PDEs), looking into the geometric characteristics of their observable sets/regions is one of the key parts in studying the corresponding observability inequalities. However, research in this area is still far from well understood. In this paper, we first present four distinct observability inequalities within the framework of abstract evolution equations, together with their corresponding control problems. Then, for several specific evolution equations (such as wave equations, heat equations, Schrödinger equations, among others), we provide the definitions of observable sets/regions corresponding to the aforementioned inequalities. Subsequently, we review some existing results and main research methods concerning the geometric characteristics of these observable sets/regions. Finally, we outline several open problems related to the geometric characteristics of observable (and weakly observable, etc.) sets/regions.Uploaded 07-10-26 Geometric Characteristics of Observable Regions

Observability is one of the main research areas in control theory. Different forms of observability inequalities not only correspond to different control phenomena but also have their own mathematical meanings. For evolutionary partial differential equations (PDEs), looking into the geometric characteristics of their observable sets/regions is one of the key parts in studying the corresponding observability inequalities. However, research in this area is still far from well understood. In this paper, we first present four distinct observability inequalities within the framework of abstract evolution equations, together with their corresponding control problems. Then, for several specific evolution equations (such as wave equations, heat equations, Schrödinger equations, among others), we provide the definitions of observable sets/regions corresponding to the aforementioned inequalities. Subsequently, we review some existing results and main research methods concerning the geometric characteristics of these observable sets/regions. Finally, we outline several open problems related to the geometric characteristics of observable (and weakly observable, etc.) sets/regions.

Uploaded 07-10-26

]]> 2592 no More details: https://www.simonsfoundation.org/event/class-song-workshop/Uploaded 30-08-19 Fri, 06 Nov 2026 01:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/class-song-workshop/Uploaded 30-08-19 More details: https://www.simonsfoundation.org/event/class-song-workshop/

Uploaded 30-08-19

]]> 3380 no Roni Ilan: Conditions for fully gapped topological superconductivity in TI nanowiresMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Fri, 06 Nov 2026 01:00:00 -0000 full Simons Foundation Roni Ilan: Conditions for fully gapped topological superconductivity in TI nanowiresMore details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/Uploaded 14-10-19 Roni Ilan: Conditions for fully gapped topological superconductivity in TI nanowires
More details: https://www.simonsfoundation.org/event/young-research-leaders-in-topological-materials-and-beyond/

Uploaded 14-10-19

]]> 2468 no Expander graphs, particularly Ramanujan graphs, have been a major focus of research over the last five decades. This research has yielded fruitful interactions between mathematics and computer science, with applications from one field benefiting the other. In recent years, a high dimensional theory of expanders has started to emerge.Uploaded 24-10-19In this lecture, Alexander Lubotzky will survey some of the achievements and challenges of this new theory. He will explain why this theory is not just a generalization but also an area that leads to new horizons in pure mathematics (such as topological overlapping) and computer science (such as property testing and locally testable codes).More details: https://www.simonsfoundation.org/event/high-dimensional-expanders/ Fri, 06 Nov 2026 01:00:00 -0000 full Simons Foundation Expander graphs, particularly Ramanujan graphs, have been a major focus of research over the last five decades. This research has yielded fruitful interactions between mathematics and computer science, with applications from one field benefiting the other. In recent years, a high dimensional theory of expanders has started to emerge.Uploaded 24-10-19In this lecture, Alexander Lubotzky will survey some of the achievements and challenges of this new theory. He will explain why this theory is not just a generalization but also an area that leads to new horizons in pure mathematics (such as topological overlapping) and computer science (such as property testing and locally testable codes).More details: https://www.simonsfoundation.org/event/high-dimensional-expanders/ Expander graphs, particularly Ramanujan graphs, have been a major focus of research over the last five decades. This research has yielded fruitful interactions between mathematics and computer science, with applications from one field benefiting the other. In recent years, a high dimensional theory of expanders has started to emerge.

Uploaded 24-10-19

In this lecture, Alexander Lubotzky will survey some of the achievements and challenges of this new theory. He will explain why this theory is not just a generalization but also an area that leads to new horizons in pure mathematics (such as topological overlapping) and computer science (such as property testing and locally testable codes).
More details: https://www.simonsfoundation.org/event/high-dimensional-expanders/

]]> 4357 no The Geometry of Polynomials for Log-Concavity and ExpansionLog concavity is an important feature of many functions and discrete sequences appearing across mathematics, including combinatorics, algebraic geometry, convex analysis, and optimization. In this talk I will survey recent developments in our understanding of functional log concavity with a focus on applications to combinatorial inequalities and algorithms for approximate counting and sampling. At the heart of this story are rich classes of multivariate generating polynomials that give rise to discrete probability distributions that can be approximately sampled efficiently using Markov chains. The basis-generating polynomial of a matroid is a fundamental example. We will explore applications to matroids and extensions to other combinatorial structures.Uploaded 06-10-26 Fri, 06 Nov 2026 00:00:00 -0000 full Simons Foundation The Geometry of Polynomials for Log-Concavity and ExpansionLog concavity is an important feature of many functions and discrete sequences appearing across mathematics, including combinatorics, algebraic geometry, convex analysis, and optimization. In this talk I will survey recent developments in our understanding of functional log concavity with a focus on applications to combinatorial inequalities and algorithms for approximate counting and sampling. At the heart of this story are rich classes of multivariate generating polynomials that give rise to discrete probability distributions that can be approximately sampled efficiently using Markov chains. The basis-generating polynomial of a matroid is a fundamental example. We will explore applications to matroids and extensions to other combinatorial structures.Uploaded 06-10-26 The Geometry of Polynomials for Log-Concavity and Expansion

Log concavity is an important feature of many functions and discrete sequences appearing across mathematics, including combinatorics, algebraic geometry, convex analysis, and optimization. In this talk I will survey recent developments in our understanding of functional log concavity with a focus on applications to combinatorial inequalities and algorithms for approximate counting and sampling. At the heart of this story are rich classes of multivariate generating polynomials that give rise to discrete probability distributions that can be approximately sampled efficiently using Markov chains. The basis-generating polynomial of a matroid is a fundamental example. We will explore applications to matroids and extensions to other combinatorial structures.

Uploaded 06-10-26

]]> 2789 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 23:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 3701 no 3-D Anisotropic vs Classical Incompressible Navier-Stokes Equationsof the three-dimensional incompressible Navier--Stokes system (denoted by (NS)). We then present our results on the global well-posedness of the three-dimensional anisotropic Navier--Stokes system ((ANS)), which has dissipation only in the x_1 and x_2 directions. In the third part of this article, we establish regularity criteria and well-posedness results for the system (NS). We emphasize that the proofs of these results rely essentially on the anisotropic analysis developed in our study of (ANS). Finally, we present our results on lower bound estimates for the analyticity radius of solutions to both (NS) and (ANS).Uploaded 06-10-26 Thu, 05 Nov 2026 22:00:00 -0000 full Simons Foundation 3-D Anisotropic vs Classical Incompressible Navier-Stokes Equationsof the three-dimensional incompressible Navier--Stokes system (denoted by (NS)). We then present our results on the global well-posedness of the three-dimensional anisotropic Navier--Stokes system ((ANS)), which has dissipation only in the x_1 and x_2 directions. In the third part of this article, we establish regularity criteria and well-posedness results for the system (NS). We emphasize that the proofs of these results rely essentially on the anisotropic analysis developed in our study of (ANS). Finally, we present our results on lower bound estimates for the analyticity radius of solutions to both (NS) and (ANS).Uploaded 06-10-26 3-D Anisotropic vs Classical Incompressible Navier-Stokes Equations

of the three-dimensional incompressible Navier--Stokes system (denoted by (NS)). We then present our results on the global well-posedness of the three-dimensional anisotropic Navier--Stokes system ((ANS)), which has dissipation only in the x_1 and x_2 directions. In the third part of this article, we establish regularity criteria and well-posedness results for the system (NS). We emphasize that the proofs of these results rely essentially on the anisotropic analysis developed in our study of (ANS). Finally, we present our results on lower bound estimates for the analyticity radius of solutions to both (NS) and (ANS).

Uploaded 06-10-26

]]> 2999 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 21:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 4078 no Is Mathematics Education Responsive to Ecological Justice: with Embodied, Entangled, ‘Popular’ Knowledges?Uploaded 06-10-26A quarter of this century has passed by, through a devastating pandemic, and unprecedented ecological disasters, while education grapples with discourses of ‘21st century skills’. Do we better understand mathematics that can critically engage our children who live diverse lives - now and in the decades to follow? We interrogate the import of 21st century discourses for mathematics education, that reinforce hierarchies of ‘skills’ vs ‘knowledge’, to sort and segregate, and maintain a global division of work between the ‘ethereal’ and the material worlds. We bear witness to regimes of standardization and homogenization of mathematics curricula ascribing large populations of young people as “low performers”. Interdisciplinary studies of connected relationalities of knowledge and material production, inspire a recrafting of paradigms of mathematics education that invisibilize artisanal and ‘popular’ vernacular knowledges, and the livelihoods of those who have lived by the earth. Towards this end, we explore intercultural imaginaries and co-constructions of mathematics for school and work-based (not vocational) education, that are responsive to livelihoods, places and the planet, with a commitment to ecological justice. Thu, 05 Nov 2026 20:00:00 -0000 full Simons Foundation Is Mathematics Education Responsive to Ecological Justice: with Embodied, Entangled, ‘Popular’ Knowledges?Uploaded 06-10-26A quarter of this century has passed by, through a devastating pandemic, and unprecedented ecological disasters, while education grapples with discourses of ‘21st century skills’. Do we better understand mathematics that can critically engage our children who live diverse lives - now and in the decades to follow? We interrogate the import of 21st century discourses for mathematics education, that reinforce hierarchies of ‘skills’ vs ‘knowledge’, to sort and segregate, and maintain a global division of work between the ‘ethereal’ and the material worlds. We bear witness to regimes of standardization and homogenization of mathematics curricula ascribing large populations of young people as “low performers”. Interdisciplinary studies of connected relationalities of knowledge and material production, inspire a recrafting of paradigms of mathematics education that invisibilize artisanal and ‘popular’ vernacular knowledges, and the livelihoods of those who have lived by the earth. Towards this end, we explore intercultural imaginaries and co-constructions of mathematics for school and work-based (not vocational) education, that are responsive to livelihoods, places and the planet, with a commitment to ecological justice. Is Mathematics Education Responsive to Ecological Justice: with Embodied, Entangled, ‘Popular’ Knowledges?

Uploaded 06-10-26

A quarter of this century has passed by, through a devastating pandemic, and unprecedented ecological disasters, while education grapples with discourses of ‘21st century skills’. Do we better understand mathematics that can critically engage our children who live diverse lives - now and in the decades to follow? We interrogate the import of 21st century discourses for mathematics education, that reinforce hierarchies of ‘skills’ vs ‘knowledge’, to sort and segregate, and maintain a global division of work between the ‘ethereal’ and the material worlds. We bear witness to regimes of standardization and homogenization of mathematics curricula ascribing large populations of young people as “low performers”. Interdisciplinary studies of connected relationalities of knowledge and material production, inspire a recrafting of paradigms of mathematics education that invisibilize artisanal and ‘popular’ vernacular knowledges, and the livelihoods of those who have lived by the earth. Towards this end, we explore intercultural imaginaries and co-constructions of mathematics for school and work-based (not vocational) education, that are responsive to livelihoods, places and the planet, with a commitment to ecological justice.

]]> 2583 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 19:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 3203 no Algebraic Groups of Birational MapsI will present some of the recent developments on algebraic groups acting via birational maps on algebraic varieties.Uploaded 05-10-26 Thu, 05 Nov 2026 18:51:00 -0000 full Simons Foundation Algebraic Groups of Birational MapsI will present some of the recent developments on algebraic groups acting via birational maps on algebraic varieties.Uploaded 05-10-26 Algebraic Groups of Birational Maps

I will present some of the recent developments on algebraic groups acting via birational maps on algebraic varieties.

Uploaded 05-10-26

]]> 2331 no The Boundaries of Von Neumann AlgebrasThe theory of von Neumann algebras was initially developed in the 1930s by Murray and von Neumann, providing a far reaching generalization of classical measure theory. Von Neumann algebras themselves were therefore initially studied as inherently analytic objects. This perspective was reinforced, and then almost immediately afterword dismantled, by Alain Connes starting in the 1970s when he showed that there is a unique separable injective II1 factor, and then also provided the first example of rigidity phenomena in von Neumann algebras through the use of Kazhdan's property (T). The juxtaposition of these two extremes led Popa's breakthrough in establishing deformation/rigidity theory, leading to numerous other breakthroughs and a deeper understanding of structural theory of von Neumann algebras. Von Neumann algebras therefore have a rich structure and it is only by studying the field from many different perspectives that we can gain a clearer picture of these mysterious objects. Each of the perspectives from ergodic theory, Voiculescu's free probability theory, abstract harmonic analysis, and other contribute to our understanding of the area. We describe a new perspective stemming from the dynamics of boundary actions. This has its origins in the work of Ozawa on applications of amenable actions, but it has only recently been realized that these boundaries are inherent to the von Neumann algebras themselves. These boundaries allow for the incorporation of geometric boundary techniques in the von Neumann algebraic setting. We survey some properties described using these boundaries as well as some rigidity results obtained using these techniques.Uploaded 06-10-26 Thu, 05 Nov 2026 18:00:00 -0000 full Simons Foundation The Boundaries of Von Neumann AlgebrasThe theory of von Neumann algebras was initially developed in the 1930s by Murray and von Neumann, providing a far reaching generalization of classical measure theory. Von Neumann algebras themselves were therefore initially studied as inherently analytic objects. This perspective was reinforced, and then almost immediately afterword dismantled, by Alain Connes starting in the 1970s when he showed that there is a unique separable injective II1 factor, and then also provided the first example of rigidity phenomena in von Neumann algebras through the use of Kazhdan's property (T). The juxtaposition of these two extremes led Popa's breakthrough in establishing deformation/rigidity theory, leading to numerous other breakthroughs and a deeper understanding of structural theory of von Neumann algebras. Von Neumann algebras therefore have a rich structure and it is only by studying the field from many different perspectives that we can gain a clearer picture of these mysterious objects. Each of the perspectives from ergodic theory, Voiculescu's free probability theory, abstract harmonic analysis, and other contribute to our understanding of the area. We describe a new perspective stemming from the dynamics of boundary actions. This has its origins in the work of Ozawa on applications of amenable actions, but it has only recently been realized that these boundaries are inherent to the von Neumann algebras themselves. These boundaries allow for the incorporation of geometric boundary techniques in the von Neumann algebraic setting. We survey some properties described using these boundaries as well as some rigidity results obtained using these techniques.Uploaded 06-10-26 The Boundaries of Von Neumann Algebras

The theory of von Neumann algebras was initially developed in the 1930s by Murray and von Neumann, providing a far reaching generalization of classical measure theory. Von Neumann algebras themselves were therefore initially studied as inherently analytic objects. This perspective was reinforced, and then almost immediately afterword dismantled, by Alain Connes starting in the 1970s when he showed that there is a unique separable injective II1 factor, and then also provided the first example of rigidity phenomena in von Neumann algebras through the use of Kazhdan's property (T). The juxtaposition of these two extremes led Popa's breakthrough in establishing deformation/rigidity theory, leading to numerous other breakthroughs and a deeper understanding of structural theory of von Neumann algebras. Von Neumann algebras therefore have a rich structure and it is only by studying the field from many different perspectives that we can gain a clearer picture of these mysterious objects. Each of the perspectives from ergodic theory, Voiculescu's free probability theory, abstract harmonic analysis, and other contribute to our understanding of the area. We describe a new perspective stemming from the dynamics of boundary actions. This has its origins in the work of Ozawa on applications of amenable actions, but it has only recently been realized that these boundaries are inherent to the von Neumann algebras themselves. These boundaries allow for the incorporation of geometric boundary techniques in the von Neumann algebraic setting. We survey some properties described using these boundaries as well as some rigidity results obtained using these techniques.

Uploaded 06-10-26

]]> 2822 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 17:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 4379 no Stable Solutions to Reaction-Diffusion Elliptic ProblemsThe talk will concern stable solutions to reaction-diffusion elliptic PDEs. We will begin with regularity questions, first addressing the classical Laplacian. In joint work with Figalli, Ros-Oton, and Serra, we proved that stable solutions are smooth up to the optimal dimension 9, thereby solving an open problem posed by Brezis in the mid-1990s. I will describe this result and also discuss related progress and open problems for the fractional Laplacian -arising naturally in boundary reaction problems-, the p-Laplacian, and minimal surfaces.We will then turn to existence questions, starting with the Casten-Holland and Matano theorem for interior reactions, which states that no nonconstant stable solution exists in convex domains under zero Neumann boundary conditions. I will present a recent result with Cónsul and Kurzke establishing that the analogous statement fails for boundary reactions. This requires the development of a new Ginzburg-Landau theory for real-valued functions and the analysis of the half-Laplacian on the real line, for which I will present new results and open problems.Uploaded 06-10-26 Thu, 05 Nov 2026 16:00:00 -0000 full Simons Foundation Stable Solutions to Reaction-Diffusion Elliptic ProblemsThe talk will concern stable solutions to reaction-diffusion elliptic PDEs. We will begin with regularity questions, first addressing the classical Laplacian. In joint work with Figalli, Ros-Oton, and Serra, we proved that stable solutions are smooth up to the optimal dimension 9, thereby solving an open problem posed by Brezis in the mid-1990s. I will describe this result and also discuss related progress and open problems for the fractional Laplacian -arising naturally in boundary reaction problems-, the p-Laplacian, and minimal surfaces.We will then turn to existence questions, starting with the Casten-Holland and Matano theorem for interior reactions, which states that no nonconstant stable solution exists in convex domains under zero Neumann boundary conditions. I will present a recent result with Cónsul and Kurzke establishing that the analogous statement fails for boundary reactions. This requires the development of a new Ginzburg-Landau theory for real-valued functions and the analysis of the half-Laplacian on the real line, for which I will present new results and open problems.Uploaded 06-10-26 Stable Solutions to Reaction-Diffusion Elliptic Problems

The talk will concern stable solutions to reaction-diffusion elliptic PDEs. We will begin with regularity questions, first addressing the classical Laplacian. In joint work with Figalli, Ros-Oton, and Serra, we proved that stable solutions are smooth up to the optimal dimension 9, thereby solving an open problem posed by Brezis in the mid-1990s. I will describe this result and also discuss related progress and open problems for the fractional Laplacian -arising naturally in boundary reaction problems-, the p-Laplacian, and minimal surfaces.We will then turn to existence questions, starting with the Casten-Holland and Matano theorem for interior reactions, which states that no nonconstant stable solution exists in convex domains under zero Neumann boundary conditions. I will present a recent result with Cónsul and Kurzke establishing that the analogous statement fails for boundary reactions. This requires the development of a new Ginzburg-Landau theory for real-valued functions and the analysis of the half-Laplacian on the real line, for which I will present new results and open problems.

Uploaded 06-10-26

]]> 3090 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 15:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 813 no Secant Sheaves and Weil Classes on Abelian VarietiesLet K be a CM-field, i.e., a totally complex quadratic extension of a totally real field F. Let X be a g-dimensional abelian variety admitting an algebra embedding of F into the rational endomorphisms of X. Let A be the product of X and Pic^0(X). We construct an embedding e of K into the rational endomorphisms of A associated to a choice of an F-blilinear polarization on X and a totally imaginary element q in K. We get the [K:Q]-dimensional subspace HW(A,e) of Hodge Weil classes in the d-th cohomology of A, where d:=4g/[K:Q]. We detail a strategy for proving the algebraicity of the Weil classes on all deformation of (A,e,h) as a polarized abelian variety of split Weil type, where h is an e(K) compatible polarization. We then specialize to the case F=Q, so that K is an imaginary quadratic number field. We survey how the above strategy was used to prove the algebraicity of the Weil classes on polarized abelian sixfolds of split Weil type. The algebraicity of the Weil classes on all abelian fourfold of Weil type follows. The Hodge conjecture for abelian varieties of dimension at most 5 is known to follow from the latter result.Uploaded 06-10-26 Thu, 05 Nov 2026 14:00:00 -0000 full Simons Foundation Secant Sheaves and Weil Classes on Abelian VarietiesLet K be a CM-field, i.e., a totally complex quadratic extension of a totally real field F. Let X be a g-dimensional abelian variety admitting an algebra embedding of F into the rational endomorphisms of X. Let A be the product of X and Pic^0(X). We construct an embedding e of K into the rational endomorphisms of A associated to a choice of an F-blilinear polarization on X and a totally imaginary element q in K. We get the [K:Q]-dimensional subspace HW(A,e) of Hodge Weil classes in the d-th cohomology of A, where d:=4g/[K:Q]. We detail a strategy for proving the algebraicity of the Weil classes on all deformation of (A,e,h) as a polarized abelian variety of split Weil type, where h is an e(K) compatible polarization. We then specialize to the case F=Q, so that K is an imaginary quadratic number field. We survey how the above strategy was used to prove the algebraicity of the Weil classes on polarized abelian sixfolds of split Weil type. The algebraicity of the Weil classes on all abelian fourfold of Weil type follows. The Hodge conjecture for abelian varieties of dimension at most 5 is known to follow from the latter result.Uploaded 06-10-26 Secant Sheaves and Weil Classes on Abelian Varieties

Let K be a CM-field, i.e., a totally complex quadratic extension of a totally real field F. Let X be a g-dimensional abelian variety admitting an algebra embedding of F into the rational endomorphisms of X. Let A be the product of X and Pic^0(X). We construct an embedding e of K into the rational endomorphisms of A associated to a choice of an F-blilinear polarization on X and a totally imaginary element q in K. We get the [K:Q]-dimensional subspace HW(A,e) of Hodge Weil classes in the d-th cohomology of A, where d:=4g/[K:Q]. We detail a strategy for proving the algebraicity of the Weil classes on all deformation of (A,e,h) as a polarized abelian variety of split Weil type, where h is an e(K) compatible polarization. We then specialize to the case F=Q, so that K is an imaginary quadratic number field. We survey how the above strategy was used to prove the algebraicity of the Weil classes on polarized abelian sixfolds of split Weil type. The algebraicity of the Weil classes on all abelian fourfold of Weil type follows. The Hodge conjecture for abelian varieties of dimension at most 5 is known to follow from the latter result.

Uploaded 06-10-26

]]> 2991 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 13:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 775 no Computational Thresholds in High-Dimensional Statistics: The Case of Graph AlignmentGraph alignment is an instance of the NP-hard quadratic assignment problem. It consists, given the adjacency matrices A1, A2 in Rn×n of two graphs, in finding a permutation matrix Π that minimizes the Frobenius norm ∥ΠA1 −A2Π∥F . In this talk we consider the problem from the perspective of high-dimensional statistics: we aim to estimate an unknown permutation π∗ in the symmetric group Sn from the observation of two correlated random adjacency matrices A1, A2.Uploaded 06-10-26We establish the following computational thresholds. We first consider the case where A1, A2 are the adjacency matrices of two correlated Erd\H{o}s-Rényi random graphs G(n, p) in the sparse regime with average degree λ := np = O(1) and edge correlation parameter s ∈ (0, 1). We identify a critical threshold s∗ (λ) for s above which a message-passing, local algorithm succeeds at alignment –that is, recovers a fraction Ω(1) of the entries of π∗, and below which no local algorithm succeeds. This result crucially depends on an associated model of correlated random trees. We then consider the case where A1, A2 are two correlated Gaussian Wigner matrices with correlation parameter expressed as s = 1/ √ 1 + σ2 where σ is the “noise” parameter. In this setting we consider a fast spectral algorithm based on the leading eigenvectors of the matrices A1, A2, and identify the critical scaling for noise parameter σ at which the fraction of entries of π∗ correctly recovered goes from 1 − o(1) to o(1). We next consider the convex relaxation approach which obtains the doubly stochastic matrix X that minimizes ∥XA1 − A2X∥F . We obtain upper and lower bounds on the critical noise parameter σ at which a simple postprocessing of X correctly recovers a fraction 1 − o(1) of entries of π∗ . We finally identify promising future directions on i) computational thresholds for spectral methods and convex relaxation methods of practical interest, and ii) impossibility results for broad classes of algorithms, notably low degree polynomial algorithms and local search algorithms. Thu, 05 Nov 2026 12:00:00 -0000 full Simons Foundation Computational Thresholds in High-Dimensional Statistics: The Case of Graph AlignmentGraph alignment is an instance of the NP-hard quadratic assignment problem. It consists, given the adjacency matrices A1, A2 in Rn×n of two graphs, in finding a permutation matrix Π that minimizes the Frobenius norm ∥ΠA1 −A2Π∥F . In this talk we consider the problem from the perspective of high-dimensional statistics: we aim to estimate an unknown permutation π∗ in the symmetric group Sn from the observation of two correlated random adjacency matrices A1, A2.Uploaded 06-10-26We establish the following computational thresholds. We first consider the case where A1, A2 are the adjacency matrices of two correlated Erd\H{o}s-Rényi random graphs G(n, p) in the sparse regime with average degree λ := np = O(1) and edge correlation parameter s ∈ (0, 1). We identify a critical threshold s∗ (λ) for s above which a message-passing, local algorithm succeeds at alignment –that is, recovers a fraction Ω(1) of the entries of π∗, and below which no local algorithm succeeds. This result crucially depends on an associated model of correlated random trees. We then consider the case where A1, A2 are two correlated Gaussian Wigner matrices with correlation parameter expressed as s = 1/ √ 1 + σ2 where σ is the “noise” parameter. In this setting we consider a fast spectral algorithm based on the leading eigenvectors of the matrices A1, A2, and identify the critical scaling for noise parameter σ at which the fraction of entries of π∗ correctly recovered goes from 1 − o(1) to o(1). We next consider the convex relaxation approach which obtains the doubly stochastic matrix X that minimizes ∥XA1 − A2X∥F . We obtain upper and lower bounds on the critical noise parameter σ at which a simple postprocessing of X correctly recovers a fraction 1 − o(1) of entries of π∗ . We finally identify promising future directions on i) computational thresholds for spectral methods and convex relaxation methods of practical interest, and ii) impossibility results for broad classes of algorithms, notably low degree polynomial algorithms and local search algorithms. Computational Thresholds in High-Dimensional Statistics: The Case of Graph Alignment

Graph alignment is an instance of the NP-hard quadratic assignment problem. It consists, given the adjacency matrices A1, A2 in Rn×n of two graphs, in finding a permutation matrix Π that minimizes the Frobenius norm ∥ΠA1 −A2Π∥F . In this talk we consider the problem from the perspective of high-dimensional statistics: we aim to estimate an unknown permutation π∗ in the symmetric group Sn from the observation of two correlated random adjacency matrices A1, A2.

Uploaded 06-10-26

We establish the following computational thresholds. We first consider the case where A1, A2 are the adjacency matrices of two correlated Erd\H{o}s-Rényi random graphs G(n, p) in the sparse regime with average degree λ := np = O(1) and edge correlation parameter s ∈ (0, 1). We identify a critical threshold s∗ (λ) for s above which a message-passing, local algorithm succeeds at alignment –that is, recovers a fraction Ω(1) of the entries of π∗, and below which no local algorithm succeeds. This result crucially depends on an associated model of correlated random trees.

We then consider the case where A1, A2 are two correlated Gaussian Wigner matrices with correlation parameter expressed as s = 1/ √ 1 + σ2 where σ is the “noise” parameter. In this setting we consider a fast spectral algorithm based on the leading eigenvectors of the matrices A1, A2, and identify the critical scaling for noise parameter σ at which the fraction of entries of π∗ correctly recovered goes from 1 − o(1) to o(1). We next consider the convex relaxation approach which obtains the doubly stochastic matrix X that minimizes ∥XA1 − A2X∥F . We obtain upper and lower bounds on the critical noise parameter σ at which a simple postprocessing of X correctly recovers a fraction 1 − o(1) of entries of π∗ .

We finally identify promising future directions on i) computational thresholds for spectral methods and convex relaxation methods of practical interest, and ii) impossibility results for broad classes of algorithms, notably low degree polynomial algorithms and local search algorithms.

]]> 2636 no More details: https://www.simonsfoundation.org/event/chemistry-in-the-cosmos-from-simplicity-to-complexity/Uploaded 10-09-19 Thu, 05 Nov 2026 11:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/chemistry-in-the-cosmos-from-simplicity-to-complexity/Uploaded 10-09-19 More details: https://www.simonsfoundation.org/event/chemistry-in-the-cosmos-from-simplicity-to-complexity/

Uploaded 10-09-19

]]> 3941 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 11:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 3650 no Character Correspondents in Finite GroupsTwo of the most important conjectures in the representation theory of finite groups have been recently proven: Richard Brauer’s Height Zero Conjecture (1955) and John McKay’s Degree Conjecture (1971). The proofs of both rely on the Classification of Finite Simple Groups. A key idea in their resolution has been to associate, to each irreducible character of a simple group, another character of a local subgroup that, remarkably, behaves in a corresponding way. This was proposed by M. Isaacs, G. Malle and this author in 2007.In the case of the McKay Conjecture, it took nearly 20 years to fully verify this correspondence, a milestone finally achieved by M. Cabanes and B. Späth. A similar strategy was applied to Brauer’s Height Zero Conjecture for the prime 2 by L. Ruhstorfer, after the so called Gluck--Wolf--Navarro--Tiep theorem was proved, and a reduction of B. Späth and this author. For odd primes, however, G. Malle, A. Schaeffer-Fry, P. H. Tiep, and the present author had to develop an entirely different approach to finally establish the result.This idea of character correspondents is now being extended to tackle other global/local conjectures, including Alperin’s Weight Conjecture, several refinements of the McKay Conjecture, and even Feit’s Conjecture on fields of values. The purpose of this talk is to explain these developments in greater detail.Uploaded 06-10-26 Thu, 05 Nov 2026 10:00:00 -0000 full Simons Foundation Character Correspondents in Finite GroupsTwo of the most important conjectures in the representation theory of finite groups have been recently proven: Richard Brauer’s Height Zero Conjecture (1955) and John McKay’s Degree Conjecture (1971). The proofs of both rely on the Classification of Finite Simple Groups. A key idea in their resolution has been to associate, to each irreducible character of a simple group, another character of a local subgroup that, remarkably, behaves in a corresponding way. This was proposed by M. Isaacs, G. Malle and this author in 2007.In the case of the McKay Conjecture, it took nearly 20 years to fully verify this correspondence, a milestone finally achieved by M. Cabanes and B. Späth. A similar strategy was applied to Brauer’s Height Zero Conjecture for the prime 2 by L. Ruhstorfer, after the so called Gluck--Wolf--Navarro--Tiep theorem was proved, and a reduction of B. Späth and this author. For odd primes, however, G. Malle, A. Schaeffer-Fry, P. H. Tiep, and the present author had to develop an entirely different approach to finally establish the result.This idea of character correspondents is now being extended to tackle other global/local conjectures, including Alperin’s Weight Conjecture, several refinements of the McKay Conjecture, and even Feit’s Conjecture on fields of values. The purpose of this talk is to explain these developments in greater detail.Uploaded 06-10-26 Character Correspondents in Finite Groups

Two of the most important conjectures in the representation theory of finite groups have been recently proven: Richard Brauer’s Height Zero Conjecture (1955) and John McKay’s Degree Conjecture (1971). The proofs of both rely on the Classification of Finite Simple Groups. A key idea in their resolution has been to associate, to each irreducible character of a simple group, another character of a local subgroup that, remarkably, behaves in a corresponding way. This was proposed by M. Isaacs, G. Malle and this author in 2007.In the case of the McKay Conjecture, it took nearly 20 years to fully verify this correspondence, a milestone finally achieved by M. Cabanes and B. Späth. A similar strategy was applied to Brauer’s Height Zero Conjecture for the prime 2 by L. Ruhstorfer, after the so called Gluck--Wolf--Navarro--Tiep theorem was proved, and a reduction of B. Späth and this author. For odd primes, however, G. Malle, A. Schaeffer-Fry, P. H. Tiep, and the present author had to develop an entirely different approach to finally establish the result.This idea of character correspondents is now being extended to tackle other global/local conjectures, including Alperin’s Weight Conjecture, several refinements of the McKay Conjecture, and even Feit’s Conjecture on fields of values. The purpose of this talk is to explain these developments in greater detail.

Uploaded 06-10-26

]]> 2749 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 09:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 3445 no How many rational points can a curve have?I will give an overwiew of results and open problems related to the number of rational points on "nice" algebraic curves of genus at least 2 over the rational numbers (or, more generally, over algebraic number fields).Uploaded 06-10-26 Thu, 05 Nov 2026 08:00:00 -0000 full Simons Foundation How many rational points can a curve have?I will give an overwiew of results and open problems related to the number of rational points on "nice" algebraic curves of genus at least 2 over the rational numbers (or, more generally, over algebraic number fields).Uploaded 06-10-26 How many rational points can a curve have?

I will give an overwiew of results and open problems related to the number of rational points on "nice" algebraic curves of genus at least 2 over the rational numbers (or, more generally, over algebraic number fields).

Uploaded 06-10-26

]]> 2596 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 07:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 4016 no Differential Stochastic Variational Inequalities and Optimization The variational inequality (VI) provides a broad unifying setting for the study of equilibrium problems and optimization. The differential variational inequality and stochastic variational inequality are generalizations of the VI and promising modeling paradigms when dynamics and uncertainties are involved in data analysis and decision making. We first discuss the mathematical formulations and recent results of the differential VI and stochastic VI. Next we introduce the differential stochastic VI with stochastic optimization (DSVIO), an ordinary differential equation whose right-hand side is defined by a stochastic VI and solutions of several stochastic optimization problems. The DSVIO provides a powerful modeling framework for various applications in data science and artificial intelligence. We provide sufficient conditions for the existence of a solution pair for the DSVIO in the space of absolutely continuous functions and the space of measurable functions. We discuss a convergent sample average approximation and time-stepping discretization scheme for numerical solutions of the DSVIO. Finally, we show applications of the DSVIO for optimizing multimodal large model-based embodied intelligence systems for the elderly mobility.Uploaded 06-10-26 Thu, 05 Nov 2026 06:00:00 -0000 full Simons Foundation Differential Stochastic Variational Inequalities and Optimization The variational inequality (VI) provides a broad unifying setting for the study of equilibrium problems and optimization. The differential variational inequality and stochastic variational inequality are generalizations of the VI and promising modeling paradigms when dynamics and uncertainties are involved in data analysis and decision making. We first discuss the mathematical formulations and recent results of the differential VI and stochastic VI. Next we introduce the differential stochastic VI with stochastic optimization (DSVIO), an ordinary differential equation whose right-hand side is defined by a stochastic VI and solutions of several stochastic optimization problems. The DSVIO provides a powerful modeling framework for various applications in data science and artificial intelligence. We provide sufficient conditions for the existence of a solution pair for the DSVIO in the space of absolutely continuous functions and the space of measurable functions. We discuss a convergent sample average approximation and time-stepping discretization scheme for numerical solutions of the DSVIO. Finally, we show applications of the DSVIO for optimizing multimodal large model-based embodied intelligence systems for the elderly mobility.Uploaded 06-10-26 Differential Stochastic Variational Inequalities and Optimization

The variational inequality (VI) provides a broad unifying setting for the study of equilibrium problems and optimization. The differential variational inequality and stochastic variational inequality are generalizations of the VI and promising modeling paradigms when dynamics and uncertainties are involved in data analysis and decision making. We first discuss the mathematical formulations and recent results of the differential VI and stochastic VI. Next we introduce the differential stochastic VI with stochastic optimization (DSVIO), an ordinary differential equation whose right-hand side is defined by a stochastic VI and solutions of several stochastic optimization problems. The DSVIO provides a powerful modeling framework for various applications in data science and artificial intelligence. We provide sufficient conditions for the existence of a solution pair for the DSVIO in the space of absolutely continuous functions and the space of measurable functions. We discuss a convergent sample average approximation and time-stepping discretization scheme for numerical solutions of the DSVIO. Finally, we show applications of the DSVIO for optimizing multimodal large model-based embodied intelligence systems for the elderly mobility.

Uploaded 06-10-26

]]> 2671 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 05:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 930 no Recent progress in graph theory using expansionGraph expansion has long been recognised as an important and desirable property with applications in a wide range of areas in computer science and mathematics. A form of expansion known as `sublinear expansion' has been used particularly successfully in the last decade in extremal graph theory, playing a pivotal role in the progress on, and resolution of, a range of long-standing and notable problems. This talk will cover some of these advances, highlighting the role of sublinear expansion and the settings in which it is effective.Uploaded 05-10-26 Thu, 05 Nov 2026 04:51:00 -0000 full Simons Foundation Recent progress in graph theory using expansionGraph expansion has long been recognised as an important and desirable property with applications in a wide range of areas in computer science and mathematics. A form of expansion known as `sublinear expansion' has been used particularly successfully in the last decade in extremal graph theory, playing a pivotal role in the progress on, and resolution of, a range of long-standing and notable problems. This talk will cover some of these advances, highlighting the role of sublinear expansion and the settings in which it is effective.Uploaded 05-10-26 Recent progress in graph theory using expansion

Graph expansion has long been recognised as an important and desirable property with applications in a wide range of areas in computer science and mathematics. A form of expansion known as `sublinear expansion' has been used particularly successfully in the last decade in extremal graph theory, playing a pivotal role in the progress on, and resolution of, a range of long-standing and notable problems. This talk will cover some of these advances, highlighting the role of sublinear expansion and the settings in which it is effective.

Uploaded 05-10-26

]]> 2736 no Mixed Non-Abelian Hodge Theory and the Linear Shafarevich ConjectureFor a complex algebraic variety X, classical Hodge theory imposes extra structure on the singular cohomology Hk(X,C) of X using the theory of harmonic forms. Non-abelian Hodge theory similarly enriches the geometry of the algebraic variety of representations of the fundamental group (which is thought of as H1(X,GLr(C))) by using harmonic metrics on local systems. The theory in the "pure" case of smooth projective X was largely worked out in the 1990s beginning with the seminal work of Simpson and has seen many applications, for example the proof of Eyssidieux--Katzarkov--Pantev--Ramachandran of the linear Shafarevich conjecture for such X. In this talk, I will survey recent advances in the "mixed" case of arbitrary complex algebraic varieties X, and show how these tools can be used to prove a number of important results about the topology of algebraic varieties, as well as a general version of the linear Shafarevich conjecture. This is based on joint work with Y. Brunebarbe and J. Tsimerman.Uploaded 06-10-26 Thu, 05 Nov 2026 04:00:00 -0000 full Simons Foundation Mixed Non-Abelian Hodge Theory and the Linear Shafarevich ConjectureFor a complex algebraic variety X, classical Hodge theory imposes extra structure on the singular cohomology Hk(X,C) of X using the theory of harmonic forms. Non-abelian Hodge theory similarly enriches the geometry of the algebraic variety of representations of the fundamental group (which is thought of as H1(X,GLr(C))) by using harmonic metrics on local systems. The theory in the "pure" case of smooth projective X was largely worked out in the 1990s beginning with the seminal work of Simpson and has seen many applications, for example the proof of Eyssidieux--Katzarkov--Pantev--Ramachandran of the linear Shafarevich conjecture for such X. In this talk, I will survey recent advances in the "mixed" case of arbitrary complex algebraic varieties X, and show how these tools can be used to prove a number of important results about the topology of algebraic varieties, as well as a general version of the linear Shafarevich conjecture. This is based on joint work with Y. Brunebarbe and J. Tsimerman.Uploaded 06-10-26 Mixed Non-Abelian Hodge Theory and the Linear Shafarevich Conjecture

For a complex algebraic variety X, classical Hodge theory imposes extra structure on the singular cohomology Hk(X,C) of X using the theory of harmonic forms. Non-abelian Hodge theory similarly enriches the geometry of the algebraic variety of representations of the fundamental group (which is thought of as H1(X,GLr(C))) by using harmonic metrics on local systems. The theory in the "pure" case of smooth projective X was largely worked out in the 1990s beginning with the seminal work of Simpson and has seen many applications, for example the proof of Eyssidieux--Katzarkov--Pantev--Ramachandran of the linear Shafarevich conjecture for such X. In this talk, I will survey recent advances in the "mixed" case of arbitrary complex algebraic varieties X, and show how these tools can be used to prove a number of important results about the topology of algebraic varieties, as well as a general version of the linear Shafarevich conjecture. This is based on joint work with Y. Brunebarbe and J. Tsimerman.

Uploaded 06-10-26

]]> 2821 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 03:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 4559 no Minimal Surfaces and Comparison GeometryWe discuss applications of area-minimization to the study of curvature in Riemannian geometry.Uploaded 06-10-26 Thu, 05 Nov 2026 02:00:00 -0000 full Simons Foundation Minimal Surfaces and Comparison GeometryWe discuss applications of area-minimization to the study of curvature in Riemannian geometry.Uploaded 06-10-26 Minimal Surfaces and Comparison Geometry

We discuss applications of area-minimization to the study of curvature in Riemannian geometry.

Uploaded 06-10-26

]]> 2499 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Thu, 05 Nov 2026 01:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 973 no Can Quantum Dynamics Emerge from Classical Chaos?Abstract Anosov geodesic flows are among the simplest mathematical models of deterministic chaos. We explain how, quite unexpectedly, quantum dynamics emerges from purely classical correlation functions. The underlying mechanism is the discrete Pollicott–Ruelle spectrum of the geodesic flow, revealed through microlocal analysis. This spectrum naturally arranges into vertical bands; when the rightmost band is separated from the rest by a gap, it governs an effective dynamics that mirrors quantum evolution.Uploaded 06-10-26 Thu, 05 Nov 2026 00:00:00 -0000 full Simons Foundation Can Quantum Dynamics Emerge from Classical Chaos?Abstract Anosov geodesic flows are among the simplest mathematical models of deterministic chaos. We explain how, quite unexpectedly, quantum dynamics emerges from purely classical correlation functions. The underlying mechanism is the discrete Pollicott–Ruelle spectrum of the geodesic flow, revealed through microlocal analysis. This spectrum naturally arranges into vertical bands; when the rightmost band is separated from the rest by a gap, it governs an effective dynamics that mirrors quantum evolution.Uploaded 06-10-26 Can Quantum Dynamics Emerge from Classical Chaos?

Abstract Anosov geodesic flows are among the simplest mathematical models of deterministic chaos. We explain how, quite unexpectedly, quantum dynamics emerges from purely classical correlation functions. The underlying mechanism is the discrete Pollicott–Ruelle spectrum of the geodesic flow, revealed through microlocal analysis. This spectrum naturally arranges into vertical bands; when the rightmost band is separated from the rest by a gap, it governs an effective dynamics that mirrors quantum evolution.

Uploaded 06-10-26

]]> 2941 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Wed, 04 Nov 2026 23:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 1271 no On Geometric Models in Representation TheoryGeometric models have emerged as an important tool in the representation theory of algebras. Surface models associated to gentle algebras have been particularly fruitful in advancing our understanding of their module and derived categories. We give an overview of some of the theoretical advances that geometric surface models for the derived categories of graded gentle algebras and their connections to Fukaya categories of surfaces have made possible.Uploaded 06-10-26 Wed, 04 Nov 2026 22:00:00 -0000 full Simons Foundation On Geometric Models in Representation TheoryGeometric models have emerged as an important tool in the representation theory of algebras. Surface models associated to gentle algebras have been particularly fruitful in advancing our understanding of their module and derived categories. We give an overview of some of the theoretical advances that geometric surface models for the derived categories of graded gentle algebras and their connections to Fukaya categories of surfaces have made possible.Uploaded 06-10-26 On Geometric Models in Representation Theory

Geometric models have emerged as an important tool in the representation theory of algebras. Surface models associated to gentle algebras have been particularly fruitful in advancing our understanding of their module and derived categories. We give an overview of some of the theoretical advances that geometric surface models for the derived categories of graded gentle algebras and their connections to Fukaya categories of surfaces have made possible.

Uploaded 06-10-26

]]> 2691 no More details: https://www.simonsfoundation.org/event/stringy-predictions-for-our-universe/Uploaded 12-09-19 Wed, 04 Nov 2026 21:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/stringy-predictions-for-our-universe/Uploaded 12-09-19 More details: https://www.simonsfoundation.org/event/stringy-predictions-for-our-universe/

Uploaded 12-09-19

]]> 3825 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Wed, 04 Nov 2026 21:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 4762 no Spin Glasses and the Parisi FormulaSpin glasses are models of statistical mechanics in which a large number of simple elements interact with one another in a disordered fashion. One of the fundamental results of the theory is the Parisi formula, which identifies the limit of the free energy of a large class of such models. Yet many interesting models remain out of reach of the classical theory, and direct generalizations of the Parisi formula yield invalid predictions. I will report on some partial progress towards the resolution of this problem, which also brings a new perspective on classical results.Uploaded 06-10-26 Wed, 04 Nov 2026 20:00:00 -0000 full Simons Foundation Spin Glasses and the Parisi FormulaSpin glasses are models of statistical mechanics in which a large number of simple elements interact with one another in a disordered fashion. One of the fundamental results of the theory is the Parisi formula, which identifies the limit of the free energy of a large class of such models. Yet many interesting models remain out of reach of the classical theory, and direct generalizations of the Parisi formula yield invalid predictions. I will report on some partial progress towards the resolution of this problem, which also brings a new perspective on classical results.Uploaded 06-10-26 Spin Glasses and the Parisi Formula

Spin glasses are models of statistical mechanics in which a large number of simple elements interact with one another in a disordered fashion. One of the fundamental results of the theory is the Parisi formula, which identifies the limit of the free energy of a large class of such models. Yet many interesting models remain out of reach of the classical theory, and direct generalizations of the Parisi formula yield invalid predictions. I will report on some partial progress towards the resolution of this problem, which also brings a new perspective on classical results.

Uploaded 06-10-26

]]> 2939 no More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 Wed, 04 Nov 2026 19:00:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/Uploaded 31-10-19 More details: https://www.simonsfoundation.org/event/lsstc-data-science-fellowship-program/

Uploaded 31-10-19

]]> 4179 no The Subspace Flatness ConjectureThe covering radius $\mu(\Lambda,K)$ of a convex body $K \subseteq \setR^n$ with respect to a full rank lattice $\Lambda \subseteq \setR^n$ is the minimum scaling needed so that translates of $K$ placed at every lattice point cover the whole $\setR^n$. A question going back to work of Kannan and Lov\'asz (1988) is how well the covering radius is described solely by the volume of $K$ and the density of the lattice, after projecting both into a suitable subspace. We report on significant progress on this question due to Regev and Stephens-Davidowitz (2016) who resolve this problem for ellipsoids and Reis and Rothvoss (2023) who cover the general case. We also survey applications of these results that give near-optimal bounds on the flatness constant as well as a $(\log n)^{O(n)}$-time algorithm for solving $n$-variable integer programs, following work of Dadush (2012). This is based on joint work with Victor Reis.Uploaded 06-10-26 Wed, 04 Nov 2026 18:00:00 -0000 full Simons Foundation The Subspace Flatness ConjectureThe covering radius $\mu(\Lambda,K)$ of a convex body $K \subseteq \setR^n$ with respect to a full rank lattice $\Lambda \subseteq \setR^n$ is the minimum scaling needed so that translates of $K$ placed at every lattice point cover the whole $\setR^n$. A question going back to work of Kannan and Lov\'asz (1988) is how well the covering radius is described solely by the volume of $K$ and the density of the lattice, after projecting both into a suitable subspace. We report on significant progress on this question due to Regev and Stephens-Davidowitz (2016) who resolve this problem for ellipsoids and Reis and Rothvoss (2023) who cover the general case. We also survey applications of these results that give near-optimal bounds on the flatness constant as well as a $(\log n)^{O(n)}$-time algorithm for solving $n$-variable integer programs, following work of Dadush (2012). This is based on joint work with Victor Reis.Uploaded 06-10-26 The Subspace Flatness Conjecture

The covering radius $\mu(\Lambda,K)$ of a convex body $K \subseteq \setR^n$ with respect to a full rank lattice $\Lambda \subseteq \setR^n$ is the minimum scaling needed so that translates of $K$ placed at every lattice point cover the whole $\setR^n$. A question going back to work of Kannan and Lov\'asz (1988) is how well the covering radius is described solely by the volume of $K$ and the density of the lattice, after projecting both into a suitable subspace.
We report on significant progress on this question due to Regev and Stephens-Davidowitz (2016) who resolve this problem for ellipsoids and Reis and Rothvoss (2023) who cover the general case.
We also survey applications of these results that give near-optimal bounds on the flatness constant as well as a $(\log n)^{O(n)}$-time algorithm for solving $n$-variable integer programs, following work of Dadush (2012). This is based on joint work with Victor Reis.

Uploaded 06-10-26

]]> 2989 no Created by Old Bridge Media:John Hubbell - Creative Director, Writer and Senior ProducerLance Murphey – Cinematographer, Field Director and EditorMeredith Hogan - ProducerJennifer Smart – Editor and IllustratorJonathan Kirkscey – ComposerKevin House - Audio EngineerUploaded 07-09-18Executive Producer:Philip Yam, Simons FoundationOpening Graphics:AST Studios© 2018 International Mathematical Union Wed, 04 Nov 2026 17:00:00 -0000 full Simons Foundation Created by Old Bridge Media:John Hubbell - Creative Director, Writer and Senior ProducerLance Murphey – Cinematographer, Field Director and EditorMeredith Hogan - ProducerJennifer Smart – Editor and IllustratorJonathan Kirkscey – ComposerKevin House - Audio EngineerUploaded 07-09-18Executive Producer:Philip Yam, Simons FoundationOpening Graphics:AST Studios© 2018 International Mathematical Union Created by Old Bridge Media:
John Hubbell - Creative Director, Writer and Senior Producer
Lance Murphey – Cinematographer, Field Director and Editor
Meredith Hogan - Producer
Jennifer Smart – Editor and Illustrator
Jonathan Kirkscey – Composer
Kevin House - Audio Engineer

Uploaded 07-09-18

Executive Producer:
Philip Yam, Simons Foundation

Opening Graphics:
AST Studios

© 2018 International Mathematical Union

]]> 589 no A Combinatorial Ride from Macdonald Polynomials to Schubert Calculus and BackWhen I started my Ph.D., I had never even heard of combinatorics. Adriano Garsia and Jeff Remmel eagerly stepped in and taught me that it is the study of a remarkable family of symmetric functions called Macdonald polynomials. By the time I discovered that their definition was not universally accepted, I had already been thoroughly indoctrinated. In this talk, I will share the Garsia–Remmel lessons, along with the story of how decades of playing with Young tableaux led to the development of a combinatorial architecture that underlies both these Macdonald polynomials and a branch of algebraic geometry known as Schubert calculus.Uploaded 06-10-26 Wed, 04 Nov 2026 16:00:00 -0000 full Simons Foundation A Combinatorial Ride from Macdonald Polynomials to Schubert Calculus and BackWhen I started my Ph.D., I had never even heard of combinatorics. Adriano Garsia and Jeff Remmel eagerly stepped in and taught me that it is the study of a remarkable family of symmetric functions called Macdonald polynomials. By the time I discovered that their definition was not universally accepted, I had already been thoroughly indoctrinated. In this talk, I will share the Garsia–Remmel lessons, along with the story of how decades of playing with Young tableaux led to the development of a combinatorial architecture that underlies both these Macdonald polynomials and a branch of algebraic geometry known as Schubert calculus.Uploaded 06-10-26 A Combinatorial Ride from Macdonald Polynomials to Schubert Calculus and Back

When I started my Ph.D., I had never even heard of combinatorics. Adriano Garsia and Jeff Remmel eagerly stepped in and taught me that it is the study of a remarkable family of symmetric functions called Macdonald polynomials. By the time I discovered that their definition was not universally accepted, I had already been thoroughly indoctrinated. In this talk, I will share the Garsia–Remmel lessons, along with the story of how decades of playing with Young tableaux led to the development of a combinatorial architecture that underlies both these Macdonald polynomials and a branch of algebraic geometry known as Schubert calculus.

Uploaded 06-10-26

]]> 3017 no Chapter 1, "Platonic Solids." Watch the complete interview at http://www.simonsfoundation.org/science_lives_video/egbert-brieskorn/Uploaded 30-01-15 Wed, 04 Nov 2026 15:00:00 -0000 full Simons Foundation Chapter 1, "Platonic Solids." Watch the complete interview at http://www.simonsfoundation.org/science_lives_video/egbert-brieskorn/Uploaded 30-01-15 Chapter 1, "Platonic Solids." Watch the complete interview at http://www.simonsfoundation.org/science_lives_video/egbert-brieskorn/

Uploaded 30-01-15

]]> 780 no Causal Structure and Representation Learning with Biomedical ApplicationsMassive data collection holds the promise of a better understanding of complex phenomena and, ultimately, better decisions. Representation learning has become a key driver of deep learning applications, as it allows learning latent spaces that capture important properties of the data without requiring any supervised annotations. Although representation learning has been hugely successful in predictive tasks, it can fail miserably in causal tasks including predicting the effect of a perturbation/intervention. This calls for a marriage between representation learning and causal inference. An exciting opportunity in this regard stems from the growing availability of multi-modal data (observational and perturbational, imaging-based and sequencing-based, at the single-cell level, tissue-level, and organism-level). We outline a statistical and computational framework for causal structure and representation learning motivated by fundamental biomedical questions: how to effectively use observational and perturbational data to perform causal discovery on observed causal variables; how to use multi-modal views of the system to learn causal variables; and how to design optimal perturbations.Uploaded 05-10-26 Wed, 04 Nov 2026 14:51:00 -0000 full Simons Foundation Causal Structure and Representation Learning with Biomedical ApplicationsMassive data collection holds the promise of a better understanding of complex phenomena and, ultimately, better decisions. Representation learning has become a key driver of deep learning applications, as it allows learning latent spaces that capture important properties of the data without requiring any supervised annotations. Although representation learning has been hugely successful in predictive tasks, it can fail miserably in causal tasks including predicting the effect of a perturbation/intervention. This calls for a marriage between representation learning and causal inference. An exciting opportunity in this regard stems from the growing availability of multi-modal data (observational and perturbational, imaging-based and sequencing-based, at the single-cell level, tissue-level, and organism-level). We outline a statistical and computational framework for causal structure and representation learning motivated by fundamental biomedical questions: how to effectively use observational and perturbational data to perform causal discovery on observed causal variables; how to use multi-modal views of the system to learn causal variables; and how to design optimal perturbations.Uploaded 05-10-26 Causal Structure and Representation Learning with Biomedical Applications

Massive data collection holds the promise of a better understanding of complex phenomena and, ultimately, better decisions. Representation learning has become a key driver of deep learning applications, as it allows learning latent spaces that capture important properties of the data without requiring any supervised annotations. Although representation learning has been hugely successful in predictive tasks, it can fail miserably in causal tasks including predicting the effect of a perturbation/intervention. This calls for a marriage between representation learning and causal inference. An exciting opportunity in this regard stems from the growing availability of multi-modal data (observational and perturbational, imaging-based and sequencing-based, at the single-cell level, tissue-level, and organism-level). We outline a statistical and computational framework for causal structure and representation learning motivated by fundamental biomedical questions: how to effectively use observational and perturbational data to perform causal discovery on observed causal variables; how to use multi-modal views of the system to learn causal variables; and how to design optimal perturbations.

Uploaded 05-10-26

]]> 2916 no BPS Cohomology in Geometry and Representation TheoryWe motivate and survey the theory of BPS invariants of categories and BPS cohomology of stacks, indicating applications in enumerative geometry and representation theory, as well as recent advances.Uploaded 06-10-26 Wed, 04 Nov 2026 14:00:00 -0000 full Simons Foundation BPS Cohomology in Geometry and Representation TheoryWe motivate and survey the theory of BPS invariants of categories and BPS cohomology of stacks, indicating applications in enumerative geometry and representation theory, as well as recent advances.Uploaded 06-10-26 BPS Cohomology in Geometry and Representation Theory

We motivate and survey the theory of BPS invariants of categories and BPS cohomology of stacks, indicating applications in enumerative geometry and representation theory, as well as recent advances.

Uploaded 06-10-26

]]> 2908 no Watch the rest of Yuri Manin's profile at https://www.simonsfoundation.org/science_lives_video/yuri-manin/Uploaded 20-04-15 Wed, 04 Nov 2026 13:00:00 -0000 full Simons Foundation Watch the rest of Yuri Manin's profile at https://www.simonsfoundation.org/science_lives_video/yuri-manin/Uploaded 20-04-15 Watch the rest of Yuri Manin's profile at https://www.simonsfoundation.org/science_lives_video/yuri-manin/

Uploaded 20-04-15

]]> 572 no Unramified Automorphic FormsWe will discuss recent progress on understanding everywhere unramified automorphic forms over function fields. The main application, joint with D. Gaitsgory and V. Lafforgue, is a proof of the Arthur-Ramanujan conjecture in this setting, , which describes the magnitudes of Hecke eigenvalues of cusp forms. This is ultimately obtained as a consequence of the geometric Langlands conjecture for D-modules in characteristic 0. In this talk, we will give an introduction to this circle of ideas.Uploaded 06-10-26 Wed, 04 Nov 2026 12:00:00 -0000 full Simons Foundation Unramified Automorphic FormsWe will discuss recent progress on understanding everywhere unramified automorphic forms over function fields. The main application, joint with D. Gaitsgory and V. Lafforgue, is a proof of the Arthur-Ramanujan conjecture in this setting, , which describes the magnitudes of Hecke eigenvalues of cusp forms. This is ultimately obtained as a consequence of the geometric Langlands conjecture for D-modules in characteristic 0. In this talk, we will give an introduction to this circle of ideas.Uploaded 06-10-26 Unramified Automorphic Forms

We will discuss recent progress on understanding everywhere unramified automorphic forms over function fields. The main application, joint with D. Gaitsgory and V. Lafforgue, is a proof of the Arthur-Ramanujan conjecture in this setting, , which describes the magnitudes of Hecke eigenvalues of cusp forms. This is ultimately obtained as a consequence of the geometric Langlands conjecture for D-modules in characteristic 0. In this talk, we will give an introduction to this circle of ideas.

Uploaded 06-10-26

]]> 2621 no Musical chords naturally inhabit certain topological spaces, which show the possible paths that a composer can use to move between chords.Uploaded 22-05-14http://www.simonsfoundation.org/multimedia/mathematical-impressions-making-music-with-a-mobius-strip/ Wed, 04 Nov 2026 11:00:00 -0000 full Simons Foundation Musical chords naturally inhabit certain topological spaces, which show the possible paths that a composer can use to move between chords.Uploaded 22-05-14http://www.simonsfoundation.org/multimedia/mathematical-impressions-making-music-with-a-mobius-strip/ Musical chords naturally inhabit certain topological spaces, which show the possible paths that a composer can use to move between chords.

Uploaded 22-05-14

http://www.simonsfoundation.org/multimedia/mathematical-impressions-making-music-with-a-mobius-strip/

]]> 569 no The Future of Prediction: in Conversation with Oskar MorgensternA century ago, economist Oskar Morgenstern studied what he called one of the most central and most difficult problems in the theory of prediction: predictions that actively influence outcomes. Self-fulfilling and self-negating prophecies are two extreme cases of a fundamental problem that arises with all predictions about social outcomes. People act on predictions in ways that change the course of events, a phenomenon called performativity. Morgenstern argued that performativity doomed prediction in the social world to guesswork with unforeseeable results. This talk gives an entry point to the emerging area of performative prediction that provides counterpoints to Morgenstern's pessimistic prophecy. The standard formulation of machine learning as risk minimization assumes a fixed data-generating distribution. Performative prediction extends risk minimization toward data-generating distributions that depend on the predictive model. This extension leads to the powerful algorithmic principle of repeated risk minimization, alternating risk minimization and model deployment indefinitely. Under suitable conditions, repeated risk minimization converges to a stable point, a kind of equilibrium at which the predictive model minimizes risk on the distribution it entails. We'll discuss three perspectives on performativity using ideas from economic modeling, optimization, and the theory of forecasting that contribute principled ways to reason about predictions that influences outcomes.Uploaded 06-10-26 Wed, 04 Nov 2026 10:00:00 -0000 full Simons Foundation The Future of Prediction: in Conversation with Oskar MorgensternA century ago, economist Oskar Morgenstern studied what he called one of the most central and most difficult problems in the theory of prediction: predictions that actively influence outcomes. Self-fulfilling and self-negating prophecies are two extreme cases of a fundamental problem that arises with all predictions about social outcomes. People act on predictions in ways that change the course of events, a phenomenon called performativity. Morgenstern argued that performativity doomed prediction in the social world to guesswork with unforeseeable results. This talk gives an entry point to the emerging area of performative prediction that provides counterpoints to Morgenstern's pessimistic prophecy. The standard formulation of machine learning as risk minimization assumes a fixed data-generating distribution. Performative prediction extends risk minimization toward data-generating distributions that depend on the predictive model. This extension leads to the powerful algorithmic principle of repeated risk minimization, alternating risk minimization and model deployment indefinitely. Under suitable conditions, repeated risk minimization converges to a stable point, a kind of equilibrium at which the predictive model minimizes risk on the distribution it entails. We'll discuss three perspectives on performativity using ideas from economic modeling, optimization, and the theory of forecasting that contribute principled ways to reason about predictions that influences outcomes.Uploaded 06-10-26 The Future of Prediction: in Conversation with Oskar Morgenstern

A century ago, economist Oskar Morgenstern studied what he called one of the most central and most difficult problems in the theory of prediction: predictions that actively influence outcomes. Self-fulfilling and self-negating prophecies are two extreme cases of a fundamental problem that arises with all predictions about social outcomes. People act on predictions in ways that change the course of events, a phenomenon called performativity. Morgenstern argued that performativity doomed prediction in the social world to guesswork with unforeseeable results. This talk gives an entry point to the emerging area of performative prediction that provides counterpoints to Morgenstern's pessimistic prophecy. The standard formulation of machine learning as risk minimization assumes a fixed data-generating distribution. Performative prediction extends risk minimization toward data-generating distributions that depend on the predictive model. This extension leads to the powerful algorithmic principle of repeated risk minimization, alternating risk minimization and model deployment indefinitely. Under suitable conditions, repeated risk minimization converges to a stable point, a kind of equilibrium at which the predictive model minimizes risk on the distribution it entails. We'll discuss three perspectives on performativity using ideas from economic modeling, optimization, and the theory of forecasting that contribute principled ways to reason about predictions that influences outcomes.

Uploaded 06-10-26

]]> 2942 no A sculpture project built entirely with right angles combines math and art in subtle and surprising ways.Uploaded 22-05-14http://www.simonsfoundation.org/multimedia/geometry-of-spaghetti-code/ Wed, 04 Nov 2026 09:00:00 -0000 full Simons Foundation A sculpture project built entirely with right angles combines math and art in subtle and surprising ways.Uploaded 22-05-14http://www.simonsfoundation.org/multimedia/geometry-of-spaghetti-code/ A sculpture project built entirely with right angles combines math and art in subtle and surprising ways.

Uploaded 22-05-14

http://www.simonsfoundation.org/multimedia/geometry-of-spaghetti-code/

]]> 676 no Watch this informational webinar to learn about the Simons Foundation’s 2027 Fellows-to-Faculty Award program, a funding opportunity for senior postdocs and early-career scientists heading into the faculty job market.The program aims to nurture new talent and broaden the community of researchers contributing to the missions of the Simons Foundation Autism Research Initiative (SFARI), the Simons Collaboration on Plasticity and the Aging Brain (SCPAB), and the Simons Collaboration on Ecological Neuroscience (SCENE).Uploaded 23-10-26For more information please visit: https://www.simonsfoundation.org/autism-neuroscience/fellows-to-faculty/ Wed, 04 Nov 2026 08:00:00 -0000 full Simons Foundation Watch this informational webinar to learn about the Simons Foundation’s 2027 Fellows-to-Faculty Award program, a funding opportunity for senior postdocs and early-career scientists heading into the faculty job market.The program aims to nurture new talent and broaden the community of researchers contributing to the missions of the Simons Foundation Autism Research Initiative (SFARI), the Simons Collaboration on Plasticity and the Aging Brain (SCPAB), and the Simons Collaboration on Ecological Neuroscience (SCENE).Uploaded 23-10-26For more information please visit: https://www.simonsfoundation.org/autism-neuroscience/fellows-to-faculty/ Watch this informational webinar to learn about the Simons Foundation’s 2027 Fellows-to-Faculty Award program, a funding opportunity for senior postdocs and early-career scientists heading into the faculty job market.

The program aims to nurture new talent and broaden the community of researchers contributing to the missions of the Simons Foundation Autism Research Initiative (SFARI), the Simons Collaboration on Plasticity and the Aging Brain (SCPAB), and the Simons Collaboration on Ecological Neuroscience (SCENE).

Uploaded 23-10-26

For more information please visit: https://www.simonsfoundation.org/autism-neuroscience/fellows-to-faculty/

]]> 4360 no More details: https://www.simonsfoundation.org/event/luck-law-and-baseball-two-stories-about-sports-and-data/Uploaded 30-09-19 Wed, 04 Nov 2026 07:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/luck-law-and-baseball-two-stories-about-sports-and-data/Uploaded 30-09-19 More details: https://www.simonsfoundation.org/event/luck-law-and-baseball-two-stories-about-sports-and-data/

Uploaded 30-09-19

]]> 4583 no A nice mathematical puzzle, with a solution anyone can understand, is to determine the direction a bicycle went when you come upon its tracks. The answer involves thinking about tangent lines, geometric constraints and the bicycle's steering mechanism.Uploaded 22-05-14http://www.simonsfoundation.org/multimedia/mathematical-impressions-bicycle-tracks/ Wed, 04 Nov 2026 07:00:00 -0000 full Simons Foundation A nice mathematical puzzle, with a solution anyone can understand, is to determine the direction a bicycle went when you come upon its tracks. The answer involves thinking about tangent lines, geometric constraints and the bicycle's steering mechanism.Uploaded 22-05-14http://www.simonsfoundation.org/multimedia/mathematical-impressions-bicycle-tracks/ A nice mathematical puzzle, with a solution anyone can understand, is to determine the direction a bicycle went when you come upon its tracks. The answer involves thinking about tangent lines, geometric constraints and the bicycle's steering mechanism.

Uploaded 22-05-14

http://www.simonsfoundation.org/multimedia/mathematical-impressions-bicycle-tracks/

]]> 575 no In this Presidential Lecture, Shep Doeleman will present the first results and the future directions of the Event Horizon Telescope (EHT). The EHT is a global array of radio dishes that successfully imaged the black hole at the center of the M87 galaxy and the black hole at the center of the Milky Way, both of which exhibit the predicted strong gravitational lensing. Subsequent observations have revealed ordered magnetic fields on horizon scales with implications for how black holes launch relativistic jets of material. What’s next? The next-generation EHT (ngEHT) is a project to expand the EHT in several ways, enabling full-color, high-definition movies of black holes to pursue the next big questions.Uploaded 26-10-26For more information please visit: https://www.simonsfoundation.org/events/taking-pictures-and-making-movies-of-supermassive-black-holes/ Wed, 04 Nov 2026 06:00:00 -0000 full Simons Foundation In this Presidential Lecture, Shep Doeleman will present the first results and the future directions of the Event Horizon Telescope (EHT). The EHT is a global array of radio dishes that successfully imaged the black hole at the center of the M87 galaxy and the black hole at the center of the Milky Way, both of which exhibit the predicted strong gravitational lensing. Subsequent observations have revealed ordered magnetic fields on horizon scales with implications for how black holes launch relativistic jets of material. What’s next? The next-generation EHT (ngEHT) is a project to expand the EHT in several ways, enabling full-color, high-definition movies of black holes to pursue the next big questions.Uploaded 26-10-26For more information please visit: https://www.simonsfoundation.org/events/taking-pictures-and-making-movies-of-supermassive-black-holes/ In this Presidential Lecture, Shep Doeleman will present the first results and the future directions of the Event Horizon Telescope (EHT). The EHT is a global array of radio dishes that successfully imaged the black hole at the center of the M87 galaxy and the black hole at the center of the Milky Way, both of which exhibit the predicted strong gravitational lensing. Subsequent observations have revealed ordered magnetic fields on horizon scales with implications for how black holes launch relativistic jets of material. What’s next? The next-generation EHT (ngEHT) is a project to expand the EHT in several ways, enabling full-color, high-definition movies of black holes to pursue the next big questions.

Uploaded 26-10-26

For more information please visit: https://www.simonsfoundation.org/events/taking-pictures-and-making-movies-of-supermassive-black-holes/

]]> 3942 no Can you combine simple observations and mathematical thinking to show that atoms exist?Uploaded 22-05-14http://www.simonsfoundation.org/multimedia/attesting-to-atoms/ Wed, 04 Nov 2026 05:00:00 -0000 full Simons Foundation Can you combine simple observations and mathematical thinking to show that atoms exist?Uploaded 22-05-14http://www.simonsfoundation.org/multimedia/attesting-to-atoms/ Can you combine simple observations and mathematical thinking to show that atoms exist?

Uploaded 22-05-14

http://www.simonsfoundation.org/multimedia/attesting-to-atoms/

]]> 569 no In this Presidential Lecture, Li Ye will discuss his research program, which seeks to understand the brain by investigating how neural circuits monitor, allocate, and utilize energy throughout the body. By combining innovative imaging technologies, chemical biology and neural circuit mapping, he and his colleagues have uncovered previously unknown pathways linking metabolism, behavior and brain activity. These discoveries reveal fundamental principles of brain-body communication and may ultimately provide new opportunities to understand and treat obesity, diabetes, neurodegenerative disorders and other diseases shaped by metabolic dysfunction.Uploaded 26-10-26For more information please visit: https://www.simonsfoundation.org/events/energetics-of-integrating-the-brain-and-body/ Wed, 04 Nov 2026 04:00:00 -0000 full Simons Foundation In this Presidential Lecture, Li Ye will discuss his research program, which seeks to understand the brain by investigating how neural circuits monitor, allocate, and utilize energy throughout the body. By combining innovative imaging technologies, chemical biology and neural circuit mapping, he and his colleagues have uncovered previously unknown pathways linking metabolism, behavior and brain activity. These discoveries reveal fundamental principles of brain-body communication and may ultimately provide new opportunities to understand and treat obesity, diabetes, neurodegenerative disorders and other diseases shaped by metabolic dysfunction.Uploaded 26-10-26For more information please visit: https://www.simonsfoundation.org/events/energetics-of-integrating-the-brain-and-body/ In this Presidential Lecture, Li Ye will discuss his research program, which seeks to understand the brain by investigating how neural circuits monitor, allocate, and utilize energy throughout the body. By combining innovative imaging technologies, chemical biology and neural circuit mapping, he and his colleagues have uncovered previously unknown pathways linking metabolism, behavior and brain activity. These discoveries reveal fundamental principles of brain-body communication and may ultimately provide new opportunities to understand and treat obesity, diabetes, neurodegenerative disorders and other diseases shaped by metabolic dysfunction.

Uploaded 26-10-26

For more information please visit: https://www.simonsfoundation.org/events/energetics-of-integrating-the-brain-and-body/

]]> 3590 no A video illustrating the beautiful geometry behind symmetrical linkages of regular polygons.Uploaded 22-05-14http://www.simonsfoundation.org/multimedia/regular-polylinks/ Wed, 04 Nov 2026 03:00:00 -0000 full Simons Foundation A video illustrating the beautiful geometry behind symmetrical linkages of regular polygons.Uploaded 22-05-14http://www.simonsfoundation.org/multimedia/regular-polylinks/ A video illustrating the beautiful geometry behind symmetrical linkages of regular polygons.

Uploaded 22-05-14

http://www.simonsfoundation.org/multimedia/regular-polylinks/

]]> 802 no Over the last twenty years, physicists have learned to manipulate individual quantum objects, such as atoms, ions, molecules, quantum circuits and electronic spins. Scientists can now build a synthetic quantum computer “atom by atom.” By controlling the interactions between atoms, scientists can study the properties of these elementary many-body systems, including quantum magnetism, transport of excitations and superconductivity, and thus gain a deeper understanding of the N-body problem. More recently, scientists realized that these quantum machines may find applications in industry, such as finding the solution of combinatorial optimization problems.Uploaded 08-11-23In this lecture, Antoine Browaeys will present an example of a synthetic quantum system based on laser-cooled ensembles of individual atoms trapped in microscopic optical tweezer arrays. By exciting the atoms to Rydberg states, he and his colleagues can make the atoms interact even at distances of more than 10 micrometers. In this way, they can study the magnetic properties of an ensemble of more than a hundred interacting one-half spins in a regime in which simulations by usual numerical methods are already very challenging. Some aspects of this research led to the creation of a startup called Pasqal. More details: https://www.simonsfoundation.org/event/exploring-many-body-problems-with-arrays-of-individual-atoms/ Wed, 04 Nov 2026 00:51:00 -0000 full Simons Foundation Over the last twenty years, physicists have learned to manipulate individual quantum objects, such as atoms, ions, molecules, quantum circuits and electronic spins. Scientists can now build a synthetic quantum computer “atom by atom.” By controlling the interactions between atoms, scientists can study the properties of these elementary many-body systems, including quantum magnetism, transport of excitations and superconductivity, and thus gain a deeper understanding of the N-body problem. More recently, scientists realized that these quantum machines may find applications in industry, such as finding the solution of combinatorial optimization problems.Uploaded 08-11-23In this lecture, Antoine Browaeys will present an example of a synthetic quantum system based on laser-cooled ensembles of individual atoms trapped in microscopic optical tweezer arrays. By exciting the atoms to Rydberg states, he and his colleagues can make the atoms interact even at distances of more than 10 micrometers. In this way, they can study the magnetic properties of an ensemble of more than a hundred interacting one-half spins in a regime in which simulations by usual numerical methods are already very challenging. Some aspects of this research led to the creation of a startup called Pasqal. More details: https://www.simonsfoundation.org/event/exploring-many-body-problems-with-arrays-of-individual-atoms/ Over the last twenty years, physicists have learned to manipulate individual quantum objects, such as atoms, ions, molecules, quantum circuits and electronic spins. Scientists can now build a synthetic quantum computer “atom by atom.” By controlling the interactions between atoms, scientists can study the properties of these elementary many-body systems, including quantum magnetism, transport of excitations and superconductivity, and thus gain a deeper understanding of the N-body problem. More recently, scientists realized that these quantum machines may find applications in industry, such as finding the solution of combinatorial optimization problems.

Uploaded 08-11-23

In this lecture, Antoine Browaeys will present an example of a synthetic quantum system based on laser-cooled ensembles of individual atoms trapped in microscopic optical tweezer arrays. By exciting the atoms to Rydberg states, he and his colleagues can make the atoms interact even at distances of more than 10 micrometers. In this way, they can study the magnetic properties of an ensemble of more than a hundred interacting one-half spins in a regime in which simulations by usual numerical methods are already very challenging. Some aspects of this research led to the creation of a startup called Pasqal. More details: https://www.simonsfoundation.org/event/exploring-many-body-problems-with-arrays-of-individual-atoms/

]]> 3986 no General anesthesia is a drug-induced, reversible condition comprised of five behavioral states: unconsciousness, amnesia (loss of memory), antinociception (loss of pain sensation), akinesia (immobility), and hemodynamic stability with control of the stress response.Uploaded 22-10-21In this lecture, Emery Brown will discuss work by him and his colleagues showing that a primary mechanism through which anesthetics create these altered states of arousal is by initiating and maintaining highly structured oscillations. These oscillations impair communication among brain regions. Brown and collaborators illustrate this effect by presenting human and non-human primate studies using high-density EEG and intracranial recordings. These studies have allowed them to give a detailed characterization of the neurophysiology of loss and recovery of consciousness due to propofol, and more recently, ketamine. In addition, they show how these dynamics change systematically with different anesthetic classes and with age.Consequently, they have developed a principled, neuroscience-based paradigm for using the EEG to monitor the brain states of patients receiving general anesthesia. In addition, they demonstrate that the state of general anesthesia can be rapidly reversed by activating specific brain circuits. Finally, they show that the state of general anesthesia can be controlled using closed-loop feedback control systems. The success of their research has depended critically on tight coupling of experiments, signal processing research and mathematical modeling. More details: https://www.simonsfoundation.org/event/rethinking-general-anesthesia/ Tue, 03 Nov 2026 17:51:00 -0000 full Simons Foundation General anesthesia is a drug-induced, reversible condition comprised of five behavioral states: unconsciousness, amnesia (loss of memory), antinociception (loss of pain sensation), akinesia (immobility), and hemodynamic stability with control of the stress response.Uploaded 22-10-21In this lecture, Emery Brown will discuss work by him and his colleagues showing that a primary mechanism through which anesthetics create these altered states of arousal is by initiating and maintaining highly structured oscillations. These oscillations impair communication among brain regions. Brown and collaborators illustrate this effect by presenting human and non-human primate studies using high-density EEG and intracranial recordings. These studies have allowed them to give a detailed characterization of the neurophysiology of loss and recovery of consciousness due to propofol, and more recently, ketamine. In addition, they show how these dynamics change systematically with different anesthetic classes and with age.Consequently, they have developed a principled, neuroscience-based paradigm for using the EEG to monitor the brain states of patients receiving general anesthesia. In addition, they demonstrate that the state of general anesthesia can be rapidly reversed by activating specific brain circuits. Finally, they show that the state of general anesthesia can be controlled using closed-loop feedback control systems. The success of their research has depended critically on tight coupling of experiments, signal processing research and mathematical modeling. More details: https://www.simonsfoundation.org/event/rethinking-general-anesthesia/ General anesthesia is a drug-induced, reversible condition comprised of five behavioral states: unconsciousness, amnesia (loss of memory), antinociception (loss of pain sensation), akinesia (immobility), and hemodynamic stability with control of the stress response.

Uploaded 22-10-21

In this lecture, Emery Brown will discuss work by him and his colleagues showing that a primary mechanism through which anesthetics create these altered states of arousal is by initiating and maintaining highly structured oscillations. These oscillations impair communication among brain regions. Brown and collaborators illustrate this effect by presenting human and non-human primate studies using high-density EEG and intracranial recordings. These studies have allowed them to give a detailed characterization of the neurophysiology of loss and recovery of consciousness due to propofol, and more recently, ketamine. In addition, they show how these dynamics change systematically with different anesthetic classes and with age.

Consequently, they have developed a principled, neuroscience-based paradigm for using the EEG to monitor the brain states of patients receiving general anesthesia. In addition, they demonstrate that the state of general anesthesia can be rapidly reversed by activating specific brain circuits. Finally, they show that the state of general anesthesia can be controlled using closed-loop feedback control systems. The success of their research has depended critically on tight coupling of experiments, signal processing research and mathematical modeling. More details: https://www.simonsfoundation.org/event/rethinking-general-anesthesia/

]]> 3267 no “I turn with terror and horror from this lamentable scourge.” Henri Poincare uttered this sentence in response to Karl Weierstrass’ famous example of a continuous curve that has no tangent at any point.Uploaded 08-11-23In this lecture, Camillo De Lellis will argue that this terrifying curve is just the first of a long series of counterintuitive mathematical objects that all share common aspects. In particular, they all result from piling up ‘appropriate waves’ at smaller and smaller scales in a suitable way. He will touch upon famous constructions of John Nash and Stephen Smale in the ’50s and ’60s, celebrated subsequent works of Mikhael Gromov, and relatively recent discoveries pertaining to the most basic equations in incompressible fluid dynamics. More details: https://www.simonsfoundation.org/event/when-reason-produces-monsters-while-it-is-wide-awake/ Tue, 03 Nov 2026 10:51:00 -0000 full Simons Foundation “I turn with terror and horror from this lamentable scourge.” Henri Poincare uttered this sentence in response to Karl Weierstrass’ famous example of a continuous curve that has no tangent at any point.Uploaded 08-11-23In this lecture, Camillo De Lellis will argue that this terrifying curve is just the first of a long series of counterintuitive mathematical objects that all share common aspects. In particular, they all result from piling up ‘appropriate waves’ at smaller and smaller scales in a suitable way. He will touch upon famous constructions of John Nash and Stephen Smale in the ’50s and ’60s, celebrated subsequent works of Mikhael Gromov, and relatively recent discoveries pertaining to the most basic equations in incompressible fluid dynamics. More details: https://www.simonsfoundation.org/event/when-reason-produces-monsters-while-it-is-wide-awake/ “I turn with terror and horror from this lamentable scourge.” Henri Poincare uttered this sentence in response to Karl Weierstrass’ famous example of a continuous curve that has no tangent at any point.

Uploaded 08-11-23

In this lecture, Camillo De Lellis will argue that this terrifying curve is just the first of a long series of counterintuitive mathematical objects that all share common aspects. In particular, they all result from piling up ‘appropriate waves’ at smaller and smaller scales in a suitable way. He will touch upon famous constructions of John Nash and Stephen Smale in the ’50s and ’60s, celebrated subsequent works of Mikhael Gromov, and relatively recent discoveries pertaining to the most basic equations in incompressible fluid dynamics. More details: https://www.simonsfoundation.org/event/when-reason-produces-monsters-while-it-is-wide-awake/

]]> 3600 no Expander graphs have been useful in computer science with versatile applications, including coding theory, networking, computational complexity and geometry.Uploaded 02-11-21High-dimensional expanders are a generalization that has been studied in recent years and hold promise for some new and exciting applications in theoretical computer science.In the talk, Irit Dinur will survey some fascinating local to global properties of high-dimensional expanders. Can these be harnessed for further computer science applications? She will describe the state-of-the-art and interesting future directions. More details: https://www.simonsfoundation.org/event/high-dimensional-expanders-in-theoretical-computer-science/ Tue, 03 Nov 2026 03:51:00 -0000 full Simons Foundation Expander graphs have been useful in computer science with versatile applications, including coding theory, networking, computational complexity and geometry.Uploaded 02-11-21High-dimensional expanders are a generalization that has been studied in recent years and hold promise for some new and exciting applications in theoretical computer science.In the talk, Irit Dinur will survey some fascinating local to global properties of high-dimensional expanders. Can these be harnessed for further computer science applications? She will describe the state-of-the-art and interesting future directions. More details: https://www.simonsfoundation.org/event/high-dimensional-expanders-in-theoretical-computer-science/ Expander graphs have been useful in computer science with versatile applications, including coding theory, networking, computational complexity and geometry.

Uploaded 02-11-21

High-dimensional expanders are a generalization that has been studied in recent years and hold promise for some new and exciting applications in theoretical computer science.

In the talk, Irit Dinur will survey some fascinating local to global properties of high-dimensional expanders. Can these be harnessed for further computer science applications? She will describe the state-of-the-art and interesting future directions. More details: https://www.simonsfoundation.org/event/high-dimensional-expanders-in-theoretical-computer-science/

]]> 3346 no Scientists love to reduce physical systems to a few elementary blocks, which they use like Lego building blocks to build more complicated ‘composite’ objects. Geoffrey Chew in the 1960s hypothesized, in connection with high-energy physics, a different type of situation. In this scenario, there are infinitely many particles, all of them equally elementary (or equally composite). The particles mutual existence is forced by tight requirements of self-consistency. He called this scheme ‘bootstrap,’ referring to a magical act of lifting oneself by one’s shoes.Uploaded 08-11-19In this lecture, Slava Rychkov will explain how the ‘bootstrap’ idea recently found a concrete realization in the theory of critical phenomena, with the three-dimensional Ising model being the simplest bootstrap system.More details: https://www.simonsfoundation.org/event/reductionism-vs-bootstrap-are-big-things-always-made-of-elementary-things/https://www.simonsfoundation.org/event/reductionism-vs-bootstrap-are-big-things-always-made-of-elementary-things/ Mon, 02 Nov 2026 20:51:00 -0000 full Simons Foundation Scientists love to reduce physical systems to a few elementary blocks, which they use like Lego building blocks to build more complicated ‘composite’ objects. Geoffrey Chew in the 1960s hypothesized, in connection with high-energy physics, a different type of situation. In this scenario, there are infinitely many particles, all of them equally elementary (or equally composite). The particles mutual existence is forced by tight requirements of self-consistency. He called this scheme ‘bootstrap,’ referring to a magical act of lifting oneself by one’s shoes.Uploaded 08-11-19In this lecture, Slava Rychkov will explain how the ‘bootstrap’ idea recently found a concrete realization in the theory of critical phenomena, with the three-dimensional Ising model being the simplest bootstrap system.More details: https://www.simonsfoundation.org/event/reductionism-vs-bootstrap-are-big-things-always-made-of-elementary-things/https://www.simonsfoundation.org/event/reductionism-vs-bootstrap-are-big-things-always-made-of-elementary-things/ Scientists love to reduce physical systems to a few elementary blocks, which they use like Lego building blocks to build more complicated ‘composite’ objects. Geoffrey Chew in the 1960s hypothesized, in connection with high-energy physics, a different type of situation. In this scenario, there are infinitely many particles, all of them equally elementary (or equally composite). The particles mutual existence is forced by tight requirements of self-consistency. He called this scheme ‘bootstrap,’ referring to a magical act of lifting oneself by one’s shoes.

Uploaded 08-11-19

In this lecture, Slava Rychkov will explain how the ‘bootstrap’ idea recently found a concrete realization in the theory of critical phenomena, with the three-dimensional Ising model being the simplest bootstrap system.
More details: https://www.simonsfoundation.org/event/reductionism-vs-bootstrap-are-big-things-always-made-of-elementary-things/https://www.simonsfoundation.org/event/reductionism-vs-bootstrap-are-big-things-always-made-of-elementary-things/

]]> 3865 no Part of the beauty of mathematics is the interplay between its different branches. In this lecture, Maxim Kontsevich will talk about a recent discovery of an unexpected relation between questions in birational algebraic geometry and the theory of automorphic forms. Computer experiments with an easy-looking system of equations played an essential role in the discovery.More details: https://www.simonsfoundation.org/event/from-equivariant-blow-ups-to-modular-symbols/Uploaded 19-11-19 Mon, 02 Nov 2026 13:51:00 -0000 full Simons Foundation Part of the beauty of mathematics is the interplay between its different branches. In this lecture, Maxim Kontsevich will talk about a recent discovery of an unexpected relation between questions in birational algebraic geometry and the theory of automorphic forms. Computer experiments with an easy-looking system of equations played an essential role in the discovery.More details: https://www.simonsfoundation.org/event/from-equivariant-blow-ups-to-modular-symbols/Uploaded 19-11-19 Part of the beauty of mathematics is the interplay between its different branches. In this lecture, Maxim Kontsevich will talk about a recent discovery of an unexpected relation between questions in birational algebraic geometry and the theory of automorphic forms. Computer experiments with an easy-looking system of equations played an essential role in the discovery.
More details: https://www.simonsfoundation.org/event/from-equivariant-blow-ups-to-modular-symbols/

Uploaded 19-11-19

]]> 3822 no Topological transition transforms common superconductivity into an exotic phase of matter, which holds promise for fault-tolerant quantum computing. A hallmark of this transition is the emergence of Majorana states. While two-dimensional semiconductor/superconductor heterostructures are desirable platforms for topological superconductivity, direct phase measurements as the fingerprint of the underlying topological transition are conspicuously missing. On gate tunable Josephson junctions made on epitaxial Al/InAs, we observe a closing and a reopening of the superconducting gap with increasing in-plane magnetic field. Since our junctions are embedded into a phase-sensitive SQUID, we are able to measure a π-jump in the superconducting phase across the junction coincident with the closing and reopening of the superconducting gap. Theoretical simulations confirm this transition is topological and compatible with the emergence of Majorana states while the magnetic field angle dependence of the transition further constrain this scenario. Remarkably, in each junction, this topological transition can be controlled by changing the gate voltage. These findings reveal versatile two-dimensional platforms for scalable topological quantum computing.More details: https://www.simonsfoundation.org/event/qclub-seminar-matthieu-dartiailh/Uploaded 22-11-19 Mon, 02 Nov 2026 06:51:00 -0000 full Simons Foundation Topological transition transforms common superconductivity into an exotic phase of matter, which holds promise for fault-tolerant quantum computing. A hallmark of this transition is the emergence of Majorana states. While two-dimensional semiconductor/superconductor heterostructures are desirable platforms for topological superconductivity, direct phase measurements as the fingerprint of the underlying topological transition are conspicuously missing. On gate tunable Josephson junctions made on epitaxial Al/InAs, we observe a closing and a reopening of the superconducting gap with increasing in-plane magnetic field. Since our junctions are embedded into a phase-sensitive SQUID, we are able to measure a π-jump in the superconducting phase across the junction coincident with the closing and reopening of the superconducting gap. Theoretical simulations confirm this transition is topological and compatible with the emergence of Majorana states while the magnetic field angle dependence of the transition further constrain this scenario. Remarkably, in each junction, this topological transition can be controlled by changing the gate voltage. These findings reveal versatile two-dimensional platforms for scalable topological quantum computing.More details: https://www.simonsfoundation.org/event/qclub-seminar-matthieu-dartiailh/Uploaded 22-11-19 Topological transition transforms common superconductivity into an exotic phase of matter, which holds promise for fault-tolerant quantum computing. A hallmark of this transition is the emergence of Majorana states. While two-dimensional semiconductor/superconductor heterostructures are desirable platforms for topological superconductivity, direct phase measurements as the fingerprint of the underlying topological transition are conspicuously missing. On gate tunable Josephson junctions made on epitaxial Al/InAs, we observe a closing and a reopening of the superconducting gap with increasing in-plane magnetic field. Since our junctions are embedded into a phase-sensitive SQUID, we are able to measure a π-jump in the superconducting phase across the junction coincident with the closing and reopening of the superconducting gap. Theoretical simulations confirm this transition is topological and compatible with the emergence of Majorana states while the magnetic field angle dependence of the transition further constrain this scenario. Remarkably, in each junction, this topological transition can be controlled by changing the gate voltage. These findings reveal versatile two-dimensional platforms for scalable topological quantum computing.
More details: https://www.simonsfoundation.org/event/qclub-seminar-matthieu-dartiailh/

Uploaded 22-11-19

]]> 2437 no Conflicts and synergies between individuality and collective behaviorCells live in communities where they interact with each other and their environment. By coordinating individuals, such interactions often result in collective behavior that emerges on scales larger than the individuals that are beneficial to the population. At the same time, populations of individuals, even isogenicones, display phenotypic heterogeneity, which diversifies individual behavior and enhances the resilience of the population in unexpected situations. This raises a dilemma: although individuality provides advantages, it also tends to reduce coordination. I will report on our recent experimental and theoretical efforts that use bacterial chemotaxis as model system to understand, the origin of individual cellular behavior and performance, and how populations of cells reconciliate individuality with group behavior.More details: https://www.simonsfoundation.org/event/ccb-colloquium-thierry-emonet/Uploaded 25-11-19 Sun, 01 Nov 2026 23:51:00 -0000 full Simons Foundation Conflicts and synergies between individuality and collective behaviorCells live in communities where they interact with each other and their environment. By coordinating individuals, such interactions often result in collective behavior that emerges on scales larger than the individuals that are beneficial to the population. At the same time, populations of individuals, even isogenicones, display phenotypic heterogeneity, which diversifies individual behavior and enhances the resilience of the population in unexpected situations. This raises a dilemma: although individuality provides advantages, it also tends to reduce coordination. I will report on our recent experimental and theoretical efforts that use bacterial chemotaxis as model system to understand, the origin of individual cellular behavior and performance, and how populations of cells reconciliate individuality with group behavior.More details: https://www.simonsfoundation.org/event/ccb-colloquium-thierry-emonet/Uploaded 25-11-19 Conflicts and synergies between individuality and collective behavior
Cells live in communities where they interact with each other and their environment. By coordinating individuals, such interactions often result in collective behavior that emerges on scales larger than the individuals that are beneficial to the population. At the same time, populations of individuals, even isogenicones, display phenotypic heterogeneity, which diversifies individual behavior and enhances the resilience of the population in unexpected situations. This raises a dilemma: although individuality provides advantages, it also tends to reduce coordination. I will report on our recent experimental and theoretical efforts that use bacterial chemotaxis as model system to understand, the origin of individual cellular behavior and performance, and how populations of cells reconciliate individuality with group behavior.
More details: https://www.simonsfoundation.org/event/ccb-colloquium-thierry-emonet/

Uploaded 25-11-19

]]> 3808 no RNA-sequencing offers the possibility to analyze the expression of all genes in a sample. However, the spatial information of gene expression is lost. In the pioneering work, a method was described that allowed studies of gene expression in tissue sections using RNA-sequencing to uncover transcriptional patterns in situ (Ståhl et al, Science, 2016). The basic concept is remarkably simple; by placing tissue sections on arrayed reverse transcription oligonucleotides with positional barcodes, cDNA for RNA-sequencing can be generated with maintained positional information within the tissue. The quality of the obtained cDNA libraries is as high as with the best protocols for homogenized tissue. Applying this strategy has been demonstrated to work remarkably well and allows visualizing and quantifying the transcriptome in regular histological tissue sections, i.e. tissue domains can be matched to precise gene expression patterns. Furthermore, data-driven methods can be applied to discover in an unsupervised manner transcriptomic patterns in space. Such patterns correspond to cell-types, microenvironments, or tissue components that allows for novel avenues of research.More details: https://www.simonsfoundation.org/event/ccb-colloquium-joakim-lunderberg/Uploaded 25-11-19 Sun, 01 Nov 2026 16:51:00 -0000 full Simons Foundation RNA-sequencing offers the possibility to analyze the expression of all genes in a sample. However, the spatial information of gene expression is lost. In the pioneering work, a method was described that allowed studies of gene expression in tissue sections using RNA-sequencing to uncover transcriptional patterns in situ (Ståhl et al, Science, 2016). The basic concept is remarkably simple; by placing tissue sections on arrayed reverse transcription oligonucleotides with positional barcodes, cDNA for RNA-sequencing can be generated with maintained positional information within the tissue. The quality of the obtained cDNA libraries is as high as with the best protocols for homogenized tissue. Applying this strategy has been demonstrated to work remarkably well and allows visualizing and quantifying the transcriptome in regular histological tissue sections, i.e. tissue domains can be matched to precise gene expression patterns. Furthermore, data-driven methods can be applied to discover in an unsupervised manner transcriptomic patterns in space. Such patterns correspond to cell-types, microenvironments, or tissue components that allows for novel avenues of research.More details: https://www.simonsfoundation.org/event/ccb-colloquium-joakim-lunderberg/Uploaded 25-11-19 RNA-sequencing offers the possibility to analyze the expression of all genes in a sample. However, the spatial information of gene expression is lost. In the pioneering work, a method was described that allowed studies of gene expression in tissue sections using RNA-sequencing to uncover transcriptional patterns in situ (Ståhl et al, Science, 2016). The basic concept is remarkably simple; by placing tissue sections on arrayed reverse transcription oligonucleotides with positional barcodes, cDNA for RNA-sequencing can be generated with maintained positional information within the tissue. The quality of the obtained cDNA libraries is as high as with the best protocols for homogenized tissue. Applying this strategy has been demonstrated to work remarkably well and allows visualizing and quantifying the transcriptome in regular histological tissue sections, i.e. tissue domains can be matched to precise gene expression patterns. Furthermore, data-driven methods can be applied to discover in an unsupervised manner transcriptomic patterns in space. Such patterns correspond to cell-types, microenvironments, or tissue components that allows for novel avenues of research.
More details: https://www.simonsfoundation.org/event/ccb-colloquium-joakim-lunderberg/

Uploaded 25-11-19

]]> 3212 no Identifying the DNA changes that underlie phenotypic adaptations is a key challenge in genomics and evolutionary biology. In the first part of the talk, I will address the fate of cis-regulatory elements in snakes that lost limbs and in subterranean mammals that have degenerated eyes. By combining genome sequencing and functional genomics with comparative analyses, we identified thousands of non-coding genomic regions that exhibit higher sequence divergence specifically in these lineages. We found that these diverged genomic regions often correspond to limb- and eye-specific regulatory elements and that sequence divergence resulted in an extensive loss of relevant transcription factor binding sites. Overall this reveals a genome-wide picture of the non-coding genomic changes involved in limb loss and eye degeneration. In the second part, I will present our work on investigating the role of gene inactivation (loss) for adaptive evolution in mammals. By developing a genomics approach to accurately detect gene-inactivating mutations and applying it to the genomes of 60 mammals, we discovered a number of lineage-specific as well as convergent gene losses that likely contribute to adaptations of different mammals to life in water or dietary specializations.More details: https://www.simonsfoundation.org/event/ccb-colloquium-michael-hiller/Uploaded 25-11-19 Sun, 01 Nov 2026 09:51:00 -0000 full Simons Foundation Identifying the DNA changes that underlie phenotypic adaptations is a key challenge in genomics and evolutionary biology. In the first part of the talk, I will address the fate of cis-regulatory elements in snakes that lost limbs and in subterranean mammals that have degenerated eyes. By combining genome sequencing and functional genomics with comparative analyses, we identified thousands of non-coding genomic regions that exhibit higher sequence divergence specifically in these lineages. We found that these diverged genomic regions often correspond to limb- and eye-specific regulatory elements and that sequence divergence resulted in an extensive loss of relevant transcription factor binding sites. Overall this reveals a genome-wide picture of the non-coding genomic changes involved in limb loss and eye degeneration. In the second part, I will present our work on investigating the role of gene inactivation (loss) for adaptive evolution in mammals. By developing a genomics approach to accurately detect gene-inactivating mutations and applying it to the genomes of 60 mammals, we discovered a number of lineage-specific as well as convergent gene losses that likely contribute to adaptations of different mammals to life in water or dietary specializations.More details: https://www.simonsfoundation.org/event/ccb-colloquium-michael-hiller/Uploaded 25-11-19 Identifying the DNA changes that underlie phenotypic adaptations is a key challenge in genomics and evolutionary biology. In the first part of the talk, I will address the fate of cis-regulatory elements in snakes that lost limbs and in subterranean mammals that have degenerated eyes. By combining genome sequencing and functional genomics with comparative analyses, we identified thousands of non-coding genomic regions that exhibit higher sequence divergence specifically in these lineages. We found that these diverged genomic regions often correspond to limb- and eye-specific regulatory elements and that sequence divergence resulted in an extensive loss of relevant transcription factor binding sites. Overall this reveals a genome-wide picture of the non-coding genomic changes involved in limb loss and eye degeneration. In the second part, I will present our work on investigating the role of gene inactivation (loss) for adaptive evolution in mammals. By developing a genomics approach to accurately detect gene-inactivating mutations and applying it to the genomes of 60 mammals, we discovered a number of lineage-specific as well as convergent gene losses that likely contribute to adaptations of different mammals to life in water or dietary specializations.
More details: https://www.simonsfoundation.org/event/ccb-colloquium-michael-hiller/

Uploaded 25-11-19

]]> 3493 no This 2-day tutorial allowed participants to prepare for the WFIRST Exoplanet Imaging Data Challenge. More details: https://www.simonsfoundation.org/event/wfirst-exoplanet-imaging-data-challenge-tutorial/Uploaded 05-12-19 Sun, 01 Nov 2026 02:51:00 -0000 full Simons Foundation This 2-day tutorial allowed participants to prepare for the WFIRST Exoplanet Imaging Data Challenge. More details: https://www.simonsfoundation.org/event/wfirst-exoplanet-imaging-data-challenge-tutorial/Uploaded 05-12-19 This 2-day tutorial allowed participants to prepare for the WFIRST Exoplanet Imaging Data Challenge. More details: https://www.simonsfoundation.org/event/wfirst-exoplanet-imaging-data-challenge-tutorial/

Uploaded 05-12-19

]]> 11077 no This 2-day tutorial allowed participants to prepare for the WFIRST Exoplanet Imaging Data Challenge. More details: https://www.simonsfoundation.org/event/wfirst-exoplanet-imaging-data-challenge-tutorial/Uploaded 05-12-19 Sat, 31 Oct 2026 19:51:00 -0000 full Simons Foundation This 2-day tutorial allowed participants to prepare for the WFIRST Exoplanet Imaging Data Challenge. More details: https://www.simonsfoundation.org/event/wfirst-exoplanet-imaging-data-challenge-tutorial/Uploaded 05-12-19 This 2-day tutorial allowed participants to prepare for the WFIRST Exoplanet Imaging Data Challenge. More details: https://www.simonsfoundation.org/event/wfirst-exoplanet-imaging-data-challenge-tutorial/

Uploaded 05-12-19

]]> 18078 no More details: https://www.simonsfoundation.org/event/cca-colloquium-rosalba-perna/Uploaded 03-01-20 Sat, 31 Oct 2026 12:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/cca-colloquium-rosalba-perna/Uploaded 03-01-20 More details: https://www.simonsfoundation.org/event/cca-colloquium-rosalba-perna/

Uploaded 03-01-20

]]> 3997 no More details: https://www.simonsfoundation.org/event/cca-colloquium-jess-werk/Uploaded 03-01-20 Sat, 31 Oct 2026 05:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/cca-colloquium-jess-werk/Uploaded 03-01-20 More details: https://www.simonsfoundation.org/event/cca-colloquium-jess-werk/

Uploaded 03-01-20

]]> 3588 no The logarithm of the characteristic polynomial of CβE matrices, viewed as a function on the unit circle in the complex plane, is a logarithmically correlated field. Ofer Zeitouni will describe joint work with Elliot Paquette, where we prove that properly centered, the maximum of this field converges to the sum of a Gumbel random variable and an independent random variable Z, thus validating a famous conjecture of Fyodorov–Hiary–Keating. If time permits, Zeitouni will describe recent work identifying the random variable ZUploaded 28-10-25 Fri, 30 Oct 2026 22:51:00 -0000 full Simons Foundation The logarithm of the characteristic polynomial of CβE matrices, viewed as a function on the unit circle in the complex plane, is a logarithmically correlated field. Ofer Zeitouni will describe joint work with Elliot Paquette, where we prove that properly centered, the maximum of this field converges to the sum of a Gumbel random variable and an independent random variable Z, thus validating a famous conjecture of Fyodorov–Hiary–Keating. If time permits, Zeitouni will describe recent work identifying the random variable ZUploaded 28-10-25 The logarithm of the characteristic polynomial of Cβ
E matrices, viewed as a function on the unit circle in the complex plane, is a logarithmically correlated field. Ofer Zeitouni will describe joint work with Elliot Paquette, where we prove that properly centered, the maximum of this field converges to the sum of a Gumbel random variable and an independent random variable Z, thus validating a famous conjecture of Fyodorov–Hiary–Keating. If time permits, Zeitouni will describe recent work identifying the random variable Z

Uploaded 28-10-25

]]> 3882 no Simulations of cosmic structure formation have come a long way. Nowadays, they are not only accurately predicting the dark matter backbone of the cosmic web and the internal structure of halos and their satellites far into the non-linear regime, but are also capable of following the baryonic sector with rapidly improving physical fidelity. In my talk, I will review the methodology and selected successes of recent hydrodynamical galaxy formation simulations, and critically discuss some of the primary uncertainties in modelling strong, scale-dependent feedback processes. I will also highlight predictions for the structure of magnetic fields in galaxies and the importance of cosmic rays in galaxy evolution. Finally, I discuss some of the challenges lying ahead in this field in the coming years. More details: https://www.simonsfoundation.org/event/cca-colloquium-volker-springel/Uploaded 03-01-20 Fri, 30 Oct 2026 15:51:00 -0000 full Simons Foundation Simulations of cosmic structure formation have come a long way. Nowadays, they are not only accurately predicting the dark matter backbone of the cosmic web and the internal structure of halos and their satellites far into the non-linear regime, but are also capable of following the baryonic sector with rapidly improving physical fidelity. In my talk, I will review the methodology and selected successes of recent hydrodynamical galaxy formation simulations, and critically discuss some of the primary uncertainties in modelling strong, scale-dependent feedback processes. I will also highlight predictions for the structure of magnetic fields in galaxies and the importance of cosmic rays in galaxy evolution. Finally, I discuss some of the challenges lying ahead in this field in the coming years. More details: https://www.simonsfoundation.org/event/cca-colloquium-volker-springel/Uploaded 03-01-20 Simulations of cosmic structure formation have come a long way. Nowadays, they are not only accurately predicting the dark matter backbone of the cosmic web and the internal structure of halos and their satellites far into the non-linear regime, but are also capable of following the baryonic sector with rapidly improving physical fidelity. In my talk, I will review the methodology and selected successes of recent hydrodynamical galaxy formation simulations, and critically discuss some of the primary uncertainties in modelling strong, scale-dependent feedback processes. I will also highlight predictions for the structure of magnetic fields in galaxies and the importance of cosmic rays in galaxy evolution. Finally, I discuss some of the challenges lying ahead in this field in the coming years. More details: https://www.simonsfoundation.org/event/cca-colloquium-volker-springel/

Uploaded 03-01-20

]]> 4286 no https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 Fri, 30 Oct 2026 08:51:00 -0000 full Simons Foundation https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/
2025 Annual Meeting of the Simons Collaboration on Moduli of Varieties
Simons Foundation
October 2-3, 2025

Uploaded 27-10-25

]]> 3743 no Supernovae (SNe) and Long-duration Gamma-ray Bursts (GRBs) are exploding stars and constitute the most powerful explosions in the universe. Since they are visible over large cosmological distances, release elements heavier than Helium, and leave behind extreme remnants such as black holes, they are fascinating objects, as well as crucial tools for many areas of astrophysics, including cosmology.Uploaded 03-01-20However, for many years the fundamental question of which stellar systems give rise to which kinds of explosions has remained outstanding: for Type Ia SNe used for cosmology as well as for Superluminous SNe and long-duration GRBs that must originate from special kinds of massive stars. I will discuss the exciting recent progress that we have made on this question in key areas by publishing and thoroughly analyzing the largest data sets in the world at the time. I will conclude with an outlook on how the most promising avenues of research – using the existing and upcoming innovative large time-domain surveys such as ZTF and LSST – will shed new light on the diverse deaths of stars. More details: https://www.simonsfoundation.org/event/cca-colloquium-maryam-modjaz/ Fri, 30 Oct 2026 01:51:00 -0000 full Simons Foundation Supernovae (SNe) and Long-duration Gamma-ray Bursts (GRBs) are exploding stars and constitute the most powerful explosions in the universe. Since they are visible over large cosmological distances, release elements heavier than Helium, and leave behind extreme remnants such as black holes, they are fascinating objects, as well as crucial tools for many areas of astrophysics, including cosmology.Uploaded 03-01-20However, for many years the fundamental question of which stellar systems give rise to which kinds of explosions has remained outstanding: for Type Ia SNe used for cosmology as well as for Superluminous SNe and long-duration GRBs that must originate from special kinds of massive stars. I will discuss the exciting recent progress that we have made on this question in key areas by publishing and thoroughly analyzing the largest data sets in the world at the time. I will conclude with an outlook on how the most promising avenues of research – using the existing and upcoming innovative large time-domain surveys such as ZTF and LSST – will shed new light on the diverse deaths of stars. More details: https://www.simonsfoundation.org/event/cca-colloquium-maryam-modjaz/ Supernovae (SNe) and Long-duration Gamma-ray Bursts (GRBs) are exploding stars and constitute the most powerful explosions in the universe. Since they are visible over large cosmological distances, release elements heavier than Helium, and leave behind extreme remnants such as black holes, they are fascinating objects, as well as crucial tools for many areas of astrophysics, including cosmology.

Uploaded 03-01-20

However, for many years the fundamental question of which stellar systems give rise to which kinds of explosions has remained outstanding: for Type Ia SNe used for cosmology as well as for Superluminous SNe and long-duration GRBs that must originate from special kinds of massive stars. I will discuss the exciting recent progress that we have made on this question in key areas by publishing and thoroughly analyzing the largest data sets in the world at the time. I will conclude with an outlook on how the most promising avenues of research – using the existing and upcoming innovative large time-domain surveys such as ZTF and LSST – will shed new light on the diverse deaths of stars. More details: https://www.simonsfoundation.org/event/cca-colloquium-maryam-modjaz/

]]> 4399 no https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 Thu, 29 Oct 2026 18:51:00 -0000 full Simons Foundation https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/
2025 Annual Meeting of the Simons Collaboration on Moduli of Varieties
Simons Foundation
October 2-3, 2025

Uploaded 27-10-25

]]> 3619 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Thu, 29 Oct 2026 11:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 4164 no https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 Thu, 29 Oct 2026 04:51:00 -0000 full Simons Foundation https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/
2025 Annual Meeting of the Simons Collaboration on Moduli of Varieties
Simons Foundation
October 2-3, 2025

Uploaded 27-10-25

]]> 3782 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Wed, 28 Oct 2026 21:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 5630 no https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 Wed, 28 Oct 2026 14:51:00 -0000 full Simons Foundation https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/
2025 Annual Meeting of the Simons Collaboration on Moduli of Varieties
Simons Foundation
October 2-3, 2025

Uploaded 27-10-25

]]> 3584 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Wed, 28 Oct 2026 07:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 5555 no https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 Wed, 28 Oct 2026 00:51:00 -0000 full Simons Foundation https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/
2025 Annual Meeting of the Simons Collaboration on Moduli of Varieties
Simons Foundation
October 2-3, 2025

Uploaded 27-10-25

]]> 3533 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Tue, 27 Oct 2026 17:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 7313 no https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 Tue, 27 Oct 2026 10:51:00 -0000 full Simons Foundation https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/
2025 Annual Meeting of the Simons Collaboration on Moduli of Varieties
Simons Foundation
October 2-3, 2025

Uploaded 27-10-25

]]> 3586 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Tue, 27 Oct 2026 03:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 4547 no https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 Mon, 26 Oct 2026 20:51:00 -0000 full Simons Foundation https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/
2025 Annual Meeting of the Simons Collaboration on Moduli of Varieties
Simons Foundation
October 2-3, 2025

Uploaded 27-10-25

]]> 3332 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Mon, 26 Oct 2026 13:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 6386 no https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 Mon, 26 Oct 2026 06:51:00 -0000 full Simons Foundation https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/2025 Annual Meeting of the Simons Collaboration on Moduli of VarietiesSimons FoundationOctober 2-3, 2025Uploaded 27-10-25 https://www.simonsfoundation.org/event/simons-collaboration-on-moduli-of-varieties-annual-meeting-2025/
2025 Annual Meeting of the Simons Collaboration on Moduli of Varieties
Simons Foundation
October 2-3, 2025

Uploaded 27-10-25

]]> 3504 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Sun, 25 Oct 2026 23:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 6314 no 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 Sun, 25 Oct 2026 16:51:00 -0000 full Simons Foundation 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meeting
https://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/

Uploaded 22-10-25

]]> 3545 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Sun, 25 Oct 2026 09:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 4204 no Peter Bartlett — Gradient Optimization Methods: Implicit Bias and Benefits of Early Stopping (Sept. 26, 2025)Uploaded 22-10-252025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/ Sun, 25 Oct 2026 02:51:00 -0000 full Simons Foundation Peter Bartlett — Gradient Optimization Methods: Implicit Bias and Benefits of Early Stopping (Sept. 26, 2025)Uploaded 22-10-252025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/ Peter Bartlett — Gradient Optimization Methods: Implicit Bias and Benefits of Early Stopping (Sept. 26, 2025)

Uploaded 22-10-25

2025 Mathematical and Scientific Foundations of Deep Learning Annual Meeting
https://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/

]]> 3795 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Sat, 24 Oct 2026 19:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 4123 no 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 Sat, 24 Oct 2026 12:51:00 -0000 full Simons Foundation 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meeting
https://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/

Uploaded 22-10-25

]]> 3702 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Sat, 24 Oct 2026 05:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 6461 no 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 Fri, 23 Oct 2026 22:51:00 -0000 full Simons Foundation 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meeting
https://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/

Uploaded 22-10-25

]]> 3653 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Fri, 23 Oct 2026 15:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 5573 no 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 Fri, 23 Oct 2026 08:51:00 -0000 full Simons Foundation 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meeting
https://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/

Uploaded 22-10-25

]]> 3743 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Fri, 23 Oct 2026 01:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 4359 no 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 Thu, 22 Oct 2026 18:51:00 -0000 full Simons Foundation 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meeting
https://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/

Uploaded 22-10-25

]]> 3490 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Thu, 22 Oct 2026 11:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 6847 no René Vidal — Learning Dynamics in the Feature-Learning Regime: Implicit Bias, Robustness, and Low-Rank AdaptationUploaded 22-10-252025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/ Thu, 22 Oct 2026 04:51:00 -0000 full Simons Foundation René Vidal — Learning Dynamics in the Feature-Learning Regime: Implicit Bias, Robustness, and Low-Rank AdaptationUploaded 22-10-252025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/ René Vidal — Learning Dynamics in the Feature-Learning Regime: Implicit Bias, Robustness, and Low-Rank Adaptation

Uploaded 22-10-25

2025 Mathematical and Scientific Foundations of Deep Learning Annual Meeting
https://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/

]]> 3849 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Wed, 21 Oct 2026 21:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 5306 no 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 Wed, 21 Oct 2026 14:51:00 -0000 full Simons Foundation 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meetinghttps://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/Uploaded 22-10-25 2025 Mathematical and Scientific Foundations of Deep Learning Annual Meeting
https://www.simonsfoundation.org/event/mathematical-and-scientific-foundations-of-deep-learning-annual-meeting-2025/

Uploaded 22-10-25

]]> 2732 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Wed, 21 Oct 2026 07:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 6720 no The International Brain Laboratory is an experiment in building a large-scale distributed collaboration committed to open science. To achieve its goals, IBL had to address problems faced by collaborations of all sizes: shared decision making, the division of labor, authorship and credit assignment, and supporting career progression. In this talk I describe some of the lessons we have learned that we hope other scientists may find applicable to their own efforts.Uploaded 20-10-25 Wed, 21 Oct 2026 00:51:00 -0000 full Simons Foundation The International Brain Laboratory is an experiment in building a large-scale distributed collaboration committed to open science. To achieve its goals, IBL had to address problems faced by collaborations of all sizes: shared decision making, the division of labor, authorship and credit assignment, and supporting career progression. In this talk I describe some of the lessons we have learned that we hope other scientists may find applicable to their own efforts.Uploaded 20-10-25 The International Brain Laboratory is an experiment in building a large-scale distributed collaboration committed to open science. To achieve its goals, IBL had to address problems faced by collaborations of all sizes: shared decision making, the division of labor, authorship and credit assignment, and supporting career progression. In this talk I describe some of the lessons we have learned that we hope other scientists may find applicable to their own efforts.

Uploaded 20-10-25

]]> 1227 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Tue, 20 Oct 2026 17:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 4251 no In this Presidential Lecture, Lilia Boeri will present cutting-edge research related to superconductivity. Eremets’ discovery of near room-temperature superconductivity in high-pressure hydrides marked a major turning point in the history of superconductivity, demonstrating that extreme pressure can stabilize phases with unprecedented properties that are unthinkable at ambient conditions. Ten years after the discovery of hydrogen sulfide superconductors, pressure quenching is emerging as a practical strategy to retain high-temperature phases at ambient pressure by preserving structures formed under extreme conditions.Uploaded 20-10-25For more information go here: https://www.simonsfoundation.org/event/designing-next-generation-superconductors-through-pressure-quenching/ Tue, 20 Oct 2026 10:51:00 -0000 full Simons Foundation In this Presidential Lecture, Lilia Boeri will present cutting-edge research related to superconductivity. Eremets’ discovery of near room-temperature superconductivity in high-pressure hydrides marked a major turning point in the history of superconductivity, demonstrating that extreme pressure can stabilize phases with unprecedented properties that are unthinkable at ambient conditions. Ten years after the discovery of hydrogen sulfide superconductors, pressure quenching is emerging as a practical strategy to retain high-temperature phases at ambient pressure by preserving structures formed under extreme conditions.Uploaded 20-10-25For more information go here: https://www.simonsfoundation.org/event/designing-next-generation-superconductors-through-pressure-quenching/ In this Presidential Lecture, Lilia Boeri will present cutting-edge research related to superconductivity. Eremets’ discovery of near room-temperature superconductivity in high-pressure hydrides marked a major turning point in the history of superconductivity, demonstrating that extreme pressure can stabilize phases with unprecedented properties that are unthinkable at ambient conditions. Ten years after the discovery of hydrogen sulfide superconductors, pressure quenching is emerging as a practical strategy to retain high-temperature phases at ambient pressure by preserving structures formed under extreme conditions.

Uploaded 20-10-25

For more information go here: https://www.simonsfoundation.org/event/designing-next-generation-superconductors-through-pressure-quenching/

]]> 4133 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Tue, 20 Oct 2026 03:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 7394 no Uploaded 20-10-25 Mon, 19 Oct 2026 20:51:00 -0000 full Simons Foundation Uploaded 20-10-25 Uploaded 20-10-25

]]> 579 no More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 Mon, 19 Oct 2026 13:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/Uploaded 10-01-20 More details: https://www.simonsfoundation.org/event/universality-turbulence-across-vast-scales-598-766/

Uploaded 10-01-20

]]> 5227 no Uploaded 20-10-25 Mon, 19 Oct 2026 06:51:00 -0000 full Simons Foundation Uploaded 20-10-25 Uploaded 20-10-25

]]> 815 no Respiratory cilia that transport mucus in the lungs, spermatozoa that collectively move through the female reproductive tract, paddling appendages that propel a crawfish, and fish swimming in a school are all examples of oscillators that exert force on a surrounding fluid. Do the synchronous or phase-shifted periodic motions that we observe arise due to hydrodynamic coupling? We will discuss experiments and models of the self-organized pattern of beating flagella and cilia — from minimal models of colloidal particles driven by optical traps to more detailed models that include dynamics of the molecular motors driving the motion. We will also consider internal coupled oscillators that model neural signaling in a model of an undulatory swimmer with sensory feedback and examine the emergent swimming behavior of the coupled fluid-neural-muscle-body system. A long-term goal of this research is to investigate the relation of spinal chord injuries to movement in a very simple system. More details: https://www.simonsfoundation.org/event/ccb-colloquium-lisa-fauci/Uploaded 13-01-20 Sun, 18 Oct 2026 23:51:00 -0000 full Simons Foundation Respiratory cilia that transport mucus in the lungs, spermatozoa that collectively move through the female reproductive tract, paddling appendages that propel a crawfish, and fish swimming in a school are all examples of oscillators that exert force on a surrounding fluid. Do the synchronous or phase-shifted periodic motions that we observe arise due to hydrodynamic coupling? We will discuss experiments and models of the self-organized pattern of beating flagella and cilia — from minimal models of colloidal particles driven by optical traps to more detailed models that include dynamics of the molecular motors driving the motion. We will also consider internal coupled oscillators that model neural signaling in a model of an undulatory swimmer with sensory feedback and examine the emergent swimming behavior of the coupled fluid-neural-muscle-body system. A long-term goal of this research is to investigate the relation of spinal chord injuries to movement in a very simple system. More details: https://www.simonsfoundation.org/event/ccb-colloquium-lisa-fauci/Uploaded 13-01-20 Respiratory cilia that transport mucus in the lungs, spermatozoa that collectively move through the female reproductive tract, paddling appendages that propel a crawfish, and fish swimming in a school are all examples of oscillators that exert force on a surrounding fluid. Do the synchronous or phase-shifted periodic motions that we observe arise due to hydrodynamic coupling? We will discuss experiments and models of the self-organized pattern of beating flagella and cilia — from minimal models of colloidal particles driven by optical traps to more detailed models that include dynamics of the molecular motors driving the motion. We will also consider internal coupled oscillators that model neural signaling in a model of an undulatory swimmer with sensory feedback and examine the emergent swimming behavior of the coupled fluid-neural-muscle-body system. A long-term goal of this research is to investigate the relation of spinal chord injuries to movement in a very simple system. More details: https://www.simonsfoundation.org/event/ccb-colloquium-lisa-fauci/

Uploaded 13-01-20

]]> 3649 no 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 Sun, 18 Oct 2026 16:51:00 -0000 full Simons Foundation 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)
https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/

Uploaded 17-10-25

]]> 3246 no Ultra-Spooky Action at a Distance: From Quantum Materials in the Lab to Black HolesThe strangest feature of quantum theory was dubbed “spooky action at a distance” by Albert Einstein. Today, scientists have convincing evidence that two quantum particles far apart can entangle with each other such that the observation of one can instantaneously determine the state of the other.Uploaded 24-01-20In this lecture, Subir Sachdev will describe how this quantum feature is playing a central role in many modern developments in physics. Quantum entanglement can occur on a macroscopic scale with trillions of electrons, leading to new forms of ‘ultra-quantum matter’ with properties of technological importance. In high-temperature superconductors, such as YBa2Cu3O7, there appears to be a ‘quantum critical point’ whose entanglement structure is being explored by experiment and theory. Related entanglement structures arise across black hole horizons, and recent advances have shed new light on Stephen Hawking’s information paradox. Sachdev will use simple models of entanglement to describe these mutually beneficial developments across different fields of physics. More details: https://www.simonsfoundation.org/event/ultra-spooky-action-at-a-distance-from-quantum-materials-in-the-lab-to-black-holes/ Sun, 18 Oct 2026 09:51:00 -0000 full Simons Foundation Ultra-Spooky Action at a Distance: From Quantum Materials in the Lab to Black HolesThe strangest feature of quantum theory was dubbed “spooky action at a distance” by Albert Einstein. Today, scientists have convincing evidence that two quantum particles far apart can entangle with each other such that the observation of one can instantaneously determine the state of the other.Uploaded 24-01-20In this lecture, Subir Sachdev will describe how this quantum feature is playing a central role in many modern developments in physics. Quantum entanglement can occur on a macroscopic scale with trillions of electrons, leading to new forms of ‘ultra-quantum matter’ with properties of technological importance. In high-temperature superconductors, such as YBa2Cu3O7, there appears to be a ‘quantum critical point’ whose entanglement structure is being explored by experiment and theory. Related entanglement structures arise across black hole horizons, and recent advances have shed new light on Stephen Hawking’s information paradox. Sachdev will use simple models of entanglement to describe these mutually beneficial developments across different fields of physics. More details: https://www.simonsfoundation.org/event/ultra-spooky-action-at-a-distance-from-quantum-materials-in-the-lab-to-black-holes/ Ultra-Spooky Action at a Distance: From Quantum Materials in the Lab to Black Holes
The strangest feature of quantum theory was dubbed “spooky action at a distance” by Albert Einstein. Today, scientists have convincing evidence that two quantum particles far apart can entangle with each other such that the observation of one can instantaneously determine the state of the other.

Uploaded 24-01-20

In this lecture, Subir Sachdev will describe how this quantum feature is playing a central role in many modern developments in physics. Quantum entanglement can occur on a macroscopic scale with trillions of electrons, leading to new forms of ‘ultra-quantum matter’ with properties of technological importance. In high-temperature superconductors, such as YBa2Cu3O7, there appears to be a ‘quantum critical point’ whose entanglement structure is being explored by experiment and theory. Related entanglement structures arise across black hole horizons, and recent advances have shed new light on Stephen Hawking’s information paradox. Sachdev will use simple models of entanglement to describe these mutually beneficial developments across different fields of physics. More details: https://www.simonsfoundation.org/event/ultra-spooky-action-at-a-distance-from-quantum-materials-in-the-lab-to-black-holes/

]]> 3646 no From Simulations to Surveys: Building Realistic Mock Catalogs for Galaxies and the CMBUploaded 17-10-252025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/ Sun, 18 Oct 2026 02:51:00 -0000 full Simons Foundation From Simulations to Surveys: Building Realistic Mock Catalogs for Galaxies and the CMBUploaded 17-10-252025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/ From Simulations to Surveys: Building Realistic Mock Catalogs for Galaxies and the CMB

Uploaded 17-10-25

2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)
https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/

]]> 3241 no If we had known back then what we know now, would we have the disorder names and categories that we do? In this lecture, Jason Lerch will explore the question: What do modern ways of looking at brains and genes tell us about autism — or autisms — and its relationship to attention deficit disorder, obsessive-compulsive disorder and other related disorders of brain development? More details: https://www.simonsfoundation.org/event/autism-autisms-or-neurodevelopmental-disorders/Uploaded 31-01-20 Sat, 17 Oct 2026 19:51:00 -0000 full Simons Foundation If we had known back then what we know now, would we have the disorder names and categories that we do? In this lecture, Jason Lerch will explore the question: What do modern ways of looking at brains and genes tell us about autism — or autisms — and its relationship to attention deficit disorder, obsessive-compulsive disorder and other related disorders of brain development? More details: https://www.simonsfoundation.org/event/autism-autisms-or-neurodevelopmental-disorders/Uploaded 31-01-20 If we had known back then what we know now, would we have the disorder names and categories that we do? In this lecture, Jason Lerch will explore the question: What do modern ways of looking at brains and genes tell us about autism — or autisms — and its relationship to attention deficit disorder, obsessive-compulsive disorder and other related disorders of brain development? More details: https://www.simonsfoundation.org/event/autism-autisms-or-neurodevelopmental-disorders/

Uploaded 31-01-20

]]> 3611 no With introduction to the collaboration by Greg Bryan.2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 Sat, 17 Oct 2026 12:51:00 -0000 full Simons Foundation With introduction to the collaboration by Greg Bryan.2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 With introduction to the collaboration by Greg Bryan.

2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)
https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/

Uploaded 17-10-25

]]> 3461 no Physical equations have their own sets of symmetries, invariants, and conserved quantities. In addition, in astrophysical contexts, systems often have many-orders-of-magnitude dynamic range and may experience supersonic speeds or discontinuities. In developing accurate, robust, and efficient scientific computing methods for high-performance simulations, one is faced with the challenge of how to discretize the equations to represent them on a computer and still maintain as many of the physical properties of the equations as possible (which typically leads to reduced numericalerror and more reliable code behavior).Uploaded 04-02-20In this talk, I will describe a variety of modern numerical techniques which I have developed and implemented in my research. These include (1) spectral methods that solve fuzzy dark matter and maintain the unitary nature of the equations, (2) a smoothed-particle hydrodynamics formulation of quantum mechanics, (3) moving-mesh finite volume methods for magnetohydrodynamics that maintain the divergence-free condition on the magnetic field and have Galilean-invariant truncation errors, and (4) collisionless (Vlasov- Poisson) dynamics on an integer lattice that obeys the Poincare recurrence theorem. This talk is meant to highlight the creativity that is involved in inventing new numerical methods, and demonstrate their usage in astrophysical applications. Sat, 17 Oct 2026 05:51:00 -0000 full Simons Foundation Physical equations have their own sets of symmetries, invariants, and conserved quantities. In addition, in astrophysical contexts, systems often have many-orders-of-magnitude dynamic range and may experience supersonic speeds or discontinuities. In developing accurate, robust, and efficient scientific computing methods for high-performance simulations, one is faced with the challenge of how to discretize the equations to represent them on a computer and still maintain as many of the physical properties of the equations as possible (which typically leads to reduced numericalerror and more reliable code behavior).Uploaded 04-02-20In this talk, I will describe a variety of modern numerical techniques which I have developed and implemented in my research. These include (1) spectral methods that solve fuzzy dark matter and maintain the unitary nature of the equations, (2) a smoothed-particle hydrodynamics formulation of quantum mechanics, (3) moving-mesh finite volume methods for magnetohydrodynamics that maintain the divergence-free condition on the magnetic field and have Galilean-invariant truncation errors, and (4) collisionless (Vlasov- Poisson) dynamics on an integer lattice that obeys the Poincare recurrence theorem. This talk is meant to highlight the creativity that is involved in inventing new numerical methods, and demonstrate their usage in astrophysical applications. Physical equations have their own sets of symmetries, invariants, and conserved quantities. In addition, in astrophysical contexts, systems often have many-orders-of-magnitude dynamic range and may experience supersonic speeds or discontinuities. In developing accurate, robust, and efficient scientific computing methods for high-performance simulations, one is faced with the challenge of how to discretize the equations to represent them on a computer and still maintain as many of the physical properties of the equations as possible (which typically leads to reduced numerical
error and more reliable code behavior).

Uploaded 04-02-20

In this talk, I will describe a variety of modern numerical techniques which I have developed and implemented in my research. These include (1) spectral methods that solve fuzzy dark matter and maintain the unitary nature of the equations, (2) a smoothed-particle hydrodynamics formulation of quantum mechanics, (3) moving-mesh finite volume methods for magnetohydrodynamics that maintain the divergence-free condition on the magnetic field and have Galilean-invariant truncation errors, and (4) collisionless (Vlasov- Poisson) dynamics on an integer lattice that obeys the Poincare recurrence theorem. This talk is meant to highlight the creativity that is involved in inventing new numerical methods, and demonstrate their usage in astrophysical applications.

]]> 3322 no 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 Fri, 16 Oct 2026 22:51:00 -0000 full Simons Foundation 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)
https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/

Uploaded 17-10-25

]]> 3163 no More info: https://www.simonsfoundation.org/event/so-theory-tutorial/Uploaded 10-02-20 Fri, 16 Oct 2026 15:51:00 -0000 full Simons Foundation More info: https://www.simonsfoundation.org/event/so-theory-tutorial/Uploaded 10-02-20 More info: https://www.simonsfoundation.org/event/so-theory-tutorial/

Uploaded 10-02-20

]]> 7030 no Bridging Galactic and Cosmological Scales: Baryonic Modeling for Next-Generation SimulationsUploaded 17-10-252025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/ Fri, 16 Oct 2026 08:51:00 -0000 full Simons Foundation Bridging Galactic and Cosmological Scales: Baryonic Modeling for Next-Generation SimulationsUploaded 17-10-252025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/ Bridging Galactic and Cosmological Scales: Baryonic Modeling for Next-Generation Simulations

Uploaded 17-10-25

2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)
https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/

]]> 3257 no Two summers ago, the LIGO interferometers detected gravitational waves from coalescing neutron stars for the first time. (Neutron stars are the dense cores left over when massive stars explode at the end of their lives). This discovery initiated a frenzied search for a visual ‘afterglow’ to the merger using dozens of telescopes on the ground and in space. Within hours, fading blue light, unlike that ever seen before, was discovered from a galaxy 100 million light-years away.Uploaded 10-02-20In this lecture, Brian Metzger will discuss the monumental importance of the first detection of gravitational waves from coalescing neutron stars. The August 2017 discovery initiated a frenzied search for a visual ‘afterglow’ to the merger using dozens of telescopes on the ground and in space. Within hours, fading blue light, unlike anything we’ve ever seen before, was discovered from a galaxy 100 million light-years away. From the debris of the merger, he and other scientists witnessed directly for the first time the creation of the heaviest elements in the universe, such as gold, silver and platinum. More details: https://www.simonsfoundation.org/event/how-gravitational-waves-pointed-us-to-the-origin-of-gold/ Fri, 16 Oct 2026 01:51:00 -0000 full Simons Foundation Two summers ago, the LIGO interferometers detected gravitational waves from coalescing neutron stars for the first time. (Neutron stars are the dense cores left over when massive stars explode at the end of their lives). This discovery initiated a frenzied search for a visual ‘afterglow’ to the merger using dozens of telescopes on the ground and in space. Within hours, fading blue light, unlike that ever seen before, was discovered from a galaxy 100 million light-years away.Uploaded 10-02-20In this lecture, Brian Metzger will discuss the monumental importance of the first detection of gravitational waves from coalescing neutron stars. The August 2017 discovery initiated a frenzied search for a visual ‘afterglow’ to the merger using dozens of telescopes on the ground and in space. Within hours, fading blue light, unlike anything we’ve ever seen before, was discovered from a galaxy 100 million light-years away. From the debris of the merger, he and other scientists witnessed directly for the first time the creation of the heaviest elements in the universe, such as gold, silver and platinum. More details: https://www.simonsfoundation.org/event/how-gravitational-waves-pointed-us-to-the-origin-of-gold/ Two summers ago, the LIGO interferometers detected gravitational waves from coalescing neutron stars for the first time. (Neutron stars are the dense cores left over when massive stars explode at the end of their lives). This discovery initiated a frenzied search for a visual ‘afterglow’ to the merger using dozens of telescopes on the ground and in space. Within hours, fading blue light, unlike that ever seen before, was discovered from a galaxy 100 million light-years away.

Uploaded 10-02-20

In this lecture, Brian Metzger will discuss the monumental importance of the first detection of gravitational waves from coalescing neutron stars. The August 2017 discovery initiated a frenzied search for a visual ‘afterglow’ to the merger using dozens of telescopes on the ground and in space. Within hours, fading blue light, unlike anything we’ve ever seen before, was discovered from a galaxy 100 million light-years away. From the debris of the merger, he and other scientists witnessed directly for the first time the creation of the heaviest elements in the universe, such as gold, silver and platinum. More details: https://www.simonsfoundation.org/event/how-gravitational-waves-pointed-us-to-the-origin-of-gold/

]]> 2803 no 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 Thu, 15 Oct 2026 18:51:00 -0000 full Simons Foundation 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)
https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/

Uploaded 17-10-25

]]> 3253 no Detection of chirping gravitational waves (GWs) at ground-based laser interferometry observatories LIGO and Virgo have uncovered a population of compact binary mergers. Forthcoming observing runs with upgraded sensitivity and more observatories joining the network will tremendously increase the number of source systems, which will shed light on their astrophysical origin and enable to exploit those events as cosmological probes. I will present independent efforts by the IAS group to analyze the publicly available LIGO/Virgo data and report newly discovered GW events in addition to what experimental collaborations have reported. I will highlight several original and crucial data analysis methodologies we have developed for template matching, noise characterization and parameter estimation. In addition, I will give outlook on gravitational lensing of cosmological GW sources as expected from forthcoming observations and envisage its applications. I will explain our new findings of how wave propagation effects, measurable with GWs but unfeasible with usual electromagnetic sources, can allow extraction of unique information to reconstruct the lens or to probe non-luminous sub-galactic dark matter structures, thereby deepening our understanding of the matter distribution in the Universe. More details: https://www.simonsfoundation.org/event/cca-special-seminar-liang-dai/Uploaded 13-02-20 Thu, 15 Oct 2026 11:51:00 -0000 full Simons Foundation Detection of chirping gravitational waves (GWs) at ground-based laser interferometry observatories LIGO and Virgo have uncovered a population of compact binary mergers. Forthcoming observing runs with upgraded sensitivity and more observatories joining the network will tremendously increase the number of source systems, which will shed light on their astrophysical origin and enable to exploit those events as cosmological probes. I will present independent efforts by the IAS group to analyze the publicly available LIGO/Virgo data and report newly discovered GW events in addition to what experimental collaborations have reported. I will highlight several original and crucial data analysis methodologies we have developed for template matching, noise characterization and parameter estimation. In addition, I will give outlook on gravitational lensing of cosmological GW sources as expected from forthcoming observations and envisage its applications. I will explain our new findings of how wave propagation effects, measurable with GWs but unfeasible with usual electromagnetic sources, can allow extraction of unique information to reconstruct the lens or to probe non-luminous sub-galactic dark matter structures, thereby deepening our understanding of the matter distribution in the Universe. More details: https://www.simonsfoundation.org/event/cca-special-seminar-liang-dai/Uploaded 13-02-20 Detection of chirping gravitational waves (GWs) at ground-based laser interferometry observatories LIGO and Virgo have uncovered a population of compact binary mergers. Forthcoming observing runs with upgraded sensitivity and more observatories joining the network will tremendously increase the number of source systems, which will shed light on their astrophysical origin and enable to exploit those events as cosmological probes. I will present independent efforts by the IAS group to analyze the publicly available LIGO/Virgo data and report newly discovered GW events in addition to what experimental collaborations have reported. I will highlight several original and crucial data analysis methodologies we have developed for template matching, noise characterization and parameter estimation. In addition, I will give outlook on gravitational lensing of cosmological GW sources as expected from forthcoming observations and envisage its applications. I will explain our new findings of how wave propagation effects, measurable with GWs but unfeasible with usual electromagnetic sources, can allow extraction of unique information to reconstruct the lens or to probe non-luminous sub-galactic dark matter structures, thereby deepening our understanding of the matter distribution in the Universe. More details: https://www.simonsfoundation.org/event/cca-special-seminar-liang-dai/

Uploaded 13-02-20

]]> 4092 no 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 Thu, 15 Oct 2026 04:51:00 -0000 full Simons Foundation 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)
https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/

Uploaded 17-10-25

]]> 2517 no Halometry—mapping out the spectrum, location, and kinematics of nonluminous structures inside the Galactic halo—can be realized via effects that variable weak gravitational lensing induces on the proper motions of stars and other luminous background sources. Modern astrometric surveys provide unprecedented positional precision along with a leap in the number of cataloged objects. Astrometry thus offers a new and sensitive probe of collapsed dark matter structures over a wide mass range, from one millionth to several million solar masses. It opens up a window into the spectrum of primordial density fluctuations with very small comoving wavenumbers, scales hitherto poorly constrained.Uploaded 13-02-20I will outline a program of detection strategies for dark matter substructure based on time-domain weak gravitational lensing, after summarizing existing techniques and constraints. I will present first results from analyses based on Gaia’s second data release. Finally, I will show that minimal models of axion-like dark matter naturally produce dense small-scale structures which can be probed by the aforementioned astrometric lensing techniques. More details: https://www.simonsfoundation.org/event/cca-special-seminar-ken-van-tilburg/ Wed, 14 Oct 2026 21:51:00 -0000 full Simons Foundation Halometry—mapping out the spectrum, location, and kinematics of nonluminous structures inside the Galactic halo—can be realized via effects that variable weak gravitational lensing induces on the proper motions of stars and other luminous background sources. Modern astrometric surveys provide unprecedented positional precision along with a leap in the number of cataloged objects. Astrometry thus offers a new and sensitive probe of collapsed dark matter structures over a wide mass range, from one millionth to several million solar masses. It opens up a window into the spectrum of primordial density fluctuations with very small comoving wavenumbers, scales hitherto poorly constrained.Uploaded 13-02-20I will outline a program of detection strategies for dark matter substructure based on time-domain weak gravitational lensing, after summarizing existing techniques and constraints. I will present first results from analyses based on Gaia’s second data release. Finally, I will show that minimal models of axion-like dark matter naturally produce dense small-scale structures which can be probed by the aforementioned astrometric lensing techniques. More details: https://www.simonsfoundation.org/event/cca-special-seminar-ken-van-tilburg/ Halometry—mapping out the spectrum, location, and kinematics of nonluminous structures inside the Galactic halo—can be realized via effects that variable weak gravitational lensing induces on the proper motions of stars and other luminous background sources. Modern astrometric surveys provide unprecedented positional precision along with a leap in the number of cataloged objects. Astrometry thus offers a new and sensitive probe of collapsed dark matter structures over a wide mass range, from one millionth to several million solar masses. It opens up a window into the spectrum of primordial density fluctuations with very small comoving wavenumbers, scales hitherto poorly constrained.

Uploaded 13-02-20

I will outline a program of detection strategies for dark matter substructure based on time-domain weak gravitational lensing, after summarizing existing techniques and constraints. I will present first results from analyses based on Gaia’s second data release. Finally, I will show that minimal models of axion-like dark matter naturally produce dense small-scale structures which can be probed by the aforementioned astrometric lensing techniques. More details: https://www.simonsfoundation.org/event/cca-special-seminar-ken-van-tilburg/

]]> 4031 no 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 Wed, 14 Oct 2026 14:51:00 -0000 full Simons Foundation 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/Uploaded 17-10-25 2025 Simons Collaboration on Learning the Universe Annual Meeting (September 18-19, 2025)
https://www.simonsfoundation.org/event/simons-collaboration-on-learning-the-universe-annual-meeting-2025/

Uploaded 17-10-25

]]> 3193 no The first quantum revolution brought us the great technological advances of the 20th century—the transistor, the laser, the atomic clock and GPS. A ‘second quantum revolution’ is now underway based on our relatively new understanding of how information can be stored, manipulated and communicated using strange quantum hardware that is neither fully digital nor fully analog.Uploaded 14-02-20In this talk, Steven Girvin will give a gentle introduction to the basic concepts that underlie this quantum information revolution. Even more remarkable than the prospect of quantum computation, he says, is the concept of quantum error correction. Rapid theoretical and experimental progress has brought us to the threshold of the era of practical quantum error correction, and it may soon become possible to carry out nearly perfect computations using imperfect hardware. More details: https://www.simonsfoundation.org/event/field-guide-to-the-second-quantum-revolution/ Wed, 14 Oct 2026 07:51:00 -0000 full Simons Foundation The first quantum revolution brought us the great technological advances of the 20th century—the transistor, the laser, the atomic clock and GPS. A ‘second quantum revolution’ is now underway based on our relatively new understanding of how information can be stored, manipulated and communicated using strange quantum hardware that is neither fully digital nor fully analog.Uploaded 14-02-20In this talk, Steven Girvin will give a gentle introduction to the basic concepts that underlie this quantum information revolution. Even more remarkable than the prospect of quantum computation, he says, is the concept of quantum error correction. Rapid theoretical and experimental progress has brought us to the threshold of the era of practical quantum error correction, and it may soon become possible to carry out nearly perfect computations using imperfect hardware. More details: https://www.simonsfoundation.org/event/field-guide-to-the-second-quantum-revolution/ The first quantum revolution brought us the great technological advances of the 20th century—the transistor, the laser, the atomic clock and GPS. A ‘second quantum revolution’ is now underway based on our relatively new understanding of how information can be stored, manipulated and communicated using strange quantum hardware that is neither fully digital nor fully analog.

Uploaded 14-02-20

In this talk, Steven Girvin will give a gentle introduction to the basic concepts that underlie this quantum information revolution. Even more remarkable than the prospect of quantum computation, he says, is the concept of quantum error correction. Rapid theoretical and experimental progress has brought us to the threshold of the era of practical quantum error correction, and it may soon become possible to carry out nearly perfect computations using imperfect hardware. More details: https://www.simonsfoundation.org/event/field-guide-to-the-second-quantum-revolution/

]]> 4072 no The neural representations of prior information about the state of the world are poorly understood. Here, to investigate them, we examined brain-wide recordings collected by the International Brain Laboratory. We report that the prior information is encoded in at least 20% to 30% of brain regions that, notably, span all levels of neural processing. This widespread representation of the prior is consistent with a neural model of Bayesian inference involving loops between areas, as opposed to a model in which the prior is incorporated only in decision-making areas.Uploaded 06-10-25The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/ Wed, 14 Oct 2026 00:51:00 -0000 full Simons Foundation The neural representations of prior information about the state of the world are poorly understood. Here, to investigate them, we examined brain-wide recordings collected by the International Brain Laboratory. We report that the prior information is encoded in at least 20% to 30% of brain regions that, notably, span all levels of neural processing. This widespread representation of the prior is consistent with a neural model of Bayesian inference involving loops between areas, as opposed to a model in which the prior is incorporated only in decision-making areas.Uploaded 06-10-25The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/ The neural representations of prior information about the state of the world are poorly understood. Here, to investigate them, we examined brain-wide recordings collected by the International Brain Laboratory. We report that the prior information is encoded in at least 20% to 30% of brain regions that, notably, span all levels of neural processing. This widespread representation of the prior is consistent with a neural model of Bayesian inference involving loops between areas, as opposed to a model in which the prior is incorporated only in decision-making areas.

Uploaded 06-10-25

The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.

For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/

]]> 1914 no The debate between Albert Einstein and Niels Bohr over the interpretation of quantum mechanics was settled by the experimental tests of Bell’s inequalities. Those experiments drew attention to the revolutionary character of quantum entanglement, which is now a key ingredient of quantum computing and quantum information.Uploaded 21-02-20In this lecture, Alain Aspect will first explain Einstein’s reasoning about entangled particles. That reasoning led to his conclusion that quantum mechanics is not complete, in contradiction with Bohr’s point of view. Aspect will then show how Bell’s inequalities have allowed experimentalists to settle the debate, emphasizing the most extraordinary features of entanglement and prompting the emergence of basic ideas for quantum information and quantum communication. These ideas are enabling the development of new technologies in many academic and industrial laboratories. More details: https://www.simonsfoundation.org/event/from-einsteins-doubts-to-quantum-technologies-a-new-quantum-revolution/ Tue, 13 Oct 2026 17:51:00 -0000 full Simons Foundation The debate between Albert Einstein and Niels Bohr over the interpretation of quantum mechanics was settled by the experimental tests of Bell’s inequalities. Those experiments drew attention to the revolutionary character of quantum entanglement, which is now a key ingredient of quantum computing and quantum information.Uploaded 21-02-20In this lecture, Alain Aspect will first explain Einstein’s reasoning about entangled particles. That reasoning led to his conclusion that quantum mechanics is not complete, in contradiction with Bohr’s point of view. Aspect will then show how Bell’s inequalities have allowed experimentalists to settle the debate, emphasizing the most extraordinary features of entanglement and prompting the emergence of basic ideas for quantum information and quantum communication. These ideas are enabling the development of new technologies in many academic and industrial laboratories. More details: https://www.simonsfoundation.org/event/from-einsteins-doubts-to-quantum-technologies-a-new-quantum-revolution/ The debate between Albert Einstein and Niels Bohr over the interpretation of quantum mechanics was settled by the experimental tests of Bell’s inequalities. Those experiments drew attention to the revolutionary character of quantum entanglement, which is now a key ingredient of quantum computing and quantum information.

Uploaded 21-02-20

In this lecture, Alain Aspect will first explain Einstein’s reasoning about entangled particles. That reasoning led to his conclusion that quantum mechanics is not complete, in contradiction with Bohr’s point of view. Aspect will then show how Bell’s inequalities have allowed experimentalists to settle the debate, emphasizing the most extraordinary features of entanglement and prompting the emergence of basic ideas for quantum information and quantum communication. These ideas are enabling the development of new technologies in many academic and industrial laboratories. More details: https://www.simonsfoundation.org/event/from-einsteins-doubts-to-quantum-technologies-a-new-quantum-revolution/

]]> 4306 no How does the brain shape mood? Answering this question is difficult. In this talk, I report that a strong neural correlate of happiness is reflected in the persistent responses of neurons in anterior insular cortex, a brain area implicated in the conscious experience of feelings.Uploaded 06-10-25The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/ Tue, 13 Oct 2026 10:51:00 -0000 full Simons Foundation How does the brain shape mood? Answering this question is difficult. In this talk, I report that a strong neural correlate of happiness is reflected in the persistent responses of neurons in anterior insular cortex, a brain area implicated in the conscious experience of feelings.Uploaded 06-10-25The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/ How does the brain shape mood? Answering this question is difficult. In this talk, I report that a strong neural correlate of happiness is reflected in the persistent responses of neurons in anterior insular cortex, a brain area implicated in the conscious experience of feelings.

Uploaded 06-10-25

The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.

For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/

]]> 2045 no A full understanding of the evolution of the universe’s structure is one of the holy grails of modern astrophysics. Astrophysicists survey large volumes of the universe and compare the findings to computer simulations. Simulating the movement of billions of particles over billions of years is a daunting task, however, even when using the simplest physical models.Uploaded 28-02-20In this lecture, Shirley Ho will discuss her team’s work building a deep neural network that learns from a set of pre-run numerical simulations and predicts the large scale structure of the universe. Extensive analysis demonstrates that their deep-learning technique outperforms the commonly used fast approximate simulation method in predicting cosmic structure in the non-linear regime. They also show that their method can accurately extrapolate far beyond its training data and predict structure formation for significantly different cosmological parameters. This ability to extrapolate outside its training set is highly unexpected and remains a mystery. More details: https://www.simonsfoundation.org/event/the-first-ai-simulation-of-the-universe-is-fast-and-accurate-and-we-dont-know-why/ Tue, 13 Oct 2026 03:51:00 -0000 full Simons Foundation A full understanding of the evolution of the universe’s structure is one of the holy grails of modern astrophysics. Astrophysicists survey large volumes of the universe and compare the findings to computer simulations. Simulating the movement of billions of particles over billions of years is a daunting task, however, even when using the simplest physical models.Uploaded 28-02-20In this lecture, Shirley Ho will discuss her team’s work building a deep neural network that learns from a set of pre-run numerical simulations and predicts the large scale structure of the universe. Extensive analysis demonstrates that their deep-learning technique outperforms the commonly used fast approximate simulation method in predicting cosmic structure in the non-linear regime. They also show that their method can accurately extrapolate far beyond its training data and predict structure formation for significantly different cosmological parameters. This ability to extrapolate outside its training set is highly unexpected and remains a mystery. More details: https://www.simonsfoundation.org/event/the-first-ai-simulation-of-the-universe-is-fast-and-accurate-and-we-dont-know-why/ A full understanding of the evolution of the universe’s structure is one of the holy grails of modern astrophysics. Astrophysicists survey large volumes of the universe and compare the findings to computer simulations. Simulating the movement of billions of particles over billions of years is a daunting task, however, even when using the simplest physical models.

Uploaded 28-02-20

In this lecture, Shirley Ho will discuss her team’s work building a deep neural network that learns from a set of pre-run numerical simulations and predicts the large scale structure of the universe. Extensive analysis demonstrates that their deep-learning technique outperforms the commonly used fast approximate simulation method in predicting cosmic structure in the non-linear regime. They also show that their method can accurately extrapolate far beyond its training data and predict structure formation for significantly different cosmological parameters. This ability to extrapolate outside its training set is highly unexpected and remains a mystery. More details: https://www.simonsfoundation.org/event/the-first-ai-simulation-of-the-universe-is-fast-and-accurate-and-we-dont-know-why/

]]> 3558 no The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.Uploaded 06-10-25For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/ Mon, 12 Oct 2026 20:51:00 -0000 full Simons Foundation The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.Uploaded 06-10-25For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/ The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.

Uploaded 06-10-25

For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/

]]> 1878 no Understanding and managing complex systems — characterized by emergent, self-organized patterns at scales larger than those of the interacting parts — has crystallized as one of the most pressing problems of our time, affecting studies in fields from biology to sociology to medicine and financial markets. Because biological systems have faced a range of challenges throughout evolutionary history that has led to a diversity of robust solutions, they are ideal for the study of complex systems, and solutions inferred from biology have successfully been applied to system design and management in other fields. It is therefore imperative not only to study individual biological systems, but also to compare broadly their organizing principles and emergent properties. The Tarnita Lab uses theoretical and empirical approaches to study the organization and emergent properties and behaviors of biological systems across spatiotemporal scales, from single cells to entire ecosystems. In this talk, Corina Tarnita will give an overview of their approach and what they have learned so far. More details: https://www.simonsfoundation.org/event/self-organization-and-robustness-in-biological-systems/Uploaded 09-03-20 Mon, 12 Oct 2026 13:51:00 -0000 full Simons Foundation Understanding and managing complex systems — characterized by emergent, self-organized patterns at scales larger than those of the interacting parts — has crystallized as one of the most pressing problems of our time, affecting studies in fields from biology to sociology to medicine and financial markets. Because biological systems have faced a range of challenges throughout evolutionary history that has led to a diversity of robust solutions, they are ideal for the study of complex systems, and solutions inferred from biology have successfully been applied to system design and management in other fields. It is therefore imperative not only to study individual biological systems, but also to compare broadly their organizing principles and emergent properties. The Tarnita Lab uses theoretical and empirical approaches to study the organization and emergent properties and behaviors of biological systems across spatiotemporal scales, from single cells to entire ecosystems. In this talk, Corina Tarnita will give an overview of their approach and what they have learned so far. More details: https://www.simonsfoundation.org/event/self-organization-and-robustness-in-biological-systems/Uploaded 09-03-20 Understanding and managing complex systems — characterized by emergent, self-organized patterns at scales larger than those of the interacting parts — has crystallized as one of the most pressing problems of our time, affecting studies in fields from biology to sociology to medicine and financial markets. Because biological systems have faced a range of challenges throughout evolutionary history that has led to a diversity of robust solutions, they are ideal for the study of complex systems, and solutions inferred from biology have successfully been applied to system design and management in other fields. It is therefore imperative not only to study individual biological systems, but also to compare broadly their organizing principles and emergent properties. The Tarnita Lab uses theoretical and empirical approaches to study the organization and emergent properties and behaviors of biological systems across spatiotemporal scales, from single cells to entire ecosystems. In this talk, Corina Tarnita will give an overview of their approach and what they have learned so far. More details: https://www.simonsfoundation.org/event/self-organization-and-robustness-in-biological-systems/

Uploaded 09-03-20

]]> 4018 no Bill Newsome recounts the origins of the Simons Collaboration on the Global Brain (SCGB), including early conversations with Jim Simons, the pivotal Buttermilk Falls workshop in June, 2012, and subsequent SCGB concept development culminating in the go-ahead signal from the Simons Foundation in fall, 2013. He also offers a larger perspective on the seminal year of 2013 that saw the launch of SCGB, the birth of the US national BRAIN initiative, and the formation of multiple prominent neuroscience efforts around the world.Uploaded 06-10-25The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/ Mon, 12 Oct 2026 06:51:00 -0000 full Simons Foundation Bill Newsome recounts the origins of the Simons Collaboration on the Global Brain (SCGB), including early conversations with Jim Simons, the pivotal Buttermilk Falls workshop in June, 2012, and subsequent SCGB concept development culminating in the go-ahead signal from the Simons Foundation in fall, 2013. He also offers a larger perspective on the seminal year of 2013 that saw the launch of SCGB, the birth of the US national BRAIN initiative, and the formation of multiple prominent neuroscience efforts around the world.Uploaded 06-10-25The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/ Bill Newsome recounts the origins of the Simons Collaboration on the Global Brain (SCGB), including early conversations with Jim Simons, the pivotal Buttermilk Falls workshop in June, 2012, and subsequent SCGB concept development culminating in the go-ahead signal from the Simons Foundation in fall, 2013. He also offers a larger perspective on the seminal year of 2013 that saw the launch of SCGB, the birth of the US national BRAIN initiative, and the formation of multiple prominent neuroscience efforts around the world.

Uploaded 06-10-25

The Simons Collaboration on the Global Brain (SCGB) aims to expand our understanding of the role of internal brain processes in the arc from sensation to action, thereby discovering the nature, role and mechanisms of the neural activity that produces cognition.

For more information please visit: https://www.simonsfoundation.org/collaborations/global-brain/

]]> 1162 no Astrostatistics is an interdisciplinary field that lives on the boundary between astronomy and statistics. This interdisciplinary field seeks to answer fundamental science questions about the universe while simultaneously inspiring new and improved statistical methods for data analysis.Uploaded 13-03-20In this talk, I will introduce two areas of my research in astrostatistics. The first covers hierarchical Bayesian analysis in the context of the Milky Way Galaxy, applied to data from the Gaia satellite. The second covers a new time series analysis method in the context of asteroseismology (the study of oscillations in stars’ interiors), applied to data from the Kepler spacecraft. The surveys performed by the Gaia satellite and the Kepler spacecraft are early examples of big data in astronomy, and thus make good testing grounds for our new astrostatistics methods in preparation for upcoming large surveys. More details: https://www.simonsfoundation.org/event/2020-spring-cca-friday-colloquium-gwen-eadie/ Sun, 11 Oct 2026 23:51:00 -0000 full Simons Foundation Astrostatistics is an interdisciplinary field that lives on the boundary between astronomy and statistics. This interdisciplinary field seeks to answer fundamental science questions about the universe while simultaneously inspiring new and improved statistical methods for data analysis.Uploaded 13-03-20In this talk, I will introduce two areas of my research in astrostatistics. The first covers hierarchical Bayesian analysis in the context of the Milky Way Galaxy, applied to data from the Gaia satellite. The second covers a new time series analysis method in the context of asteroseismology (the study of oscillations in stars’ interiors), applied to data from the Kepler spacecraft. The surveys performed by the Gaia satellite and the Kepler spacecraft are early examples of big data in astronomy, and thus make good testing grounds for our new astrostatistics methods in preparation for upcoming large surveys. More details: https://www.simonsfoundation.org/event/2020-spring-cca-friday-colloquium-gwen-eadie/ Astrostatistics is an interdisciplinary field that lives on the boundary between astronomy and statistics. This interdisciplinary field seeks to answer fundamental science questions about the universe while simultaneously inspiring new and improved statistical methods for data analysis.

Uploaded 13-03-20

In this talk, I will introduce two areas of my research in astrostatistics. The first covers hierarchical Bayesian analysis in the context of the Milky Way Galaxy, applied to data from the Gaia satellite. The second covers a new time series analysis method in the context of asteroseismology (the study of oscillations in stars’ interiors), applied to data from the Kepler spacecraft. The surveys performed by the Gaia satellite and the Kepler spacecraft are early examples of big data in astronomy, and thus make good testing grounds for our new astrostatistics methods in preparation for upcoming large surveys. More details: https://www.simonsfoundation.org/event/2020-spring-cca-friday-colloquium-gwen-eadie/

]]> 3653 no Where is Mathematics Going?~Is there a better way to do this? In this Presidential Lecture, Kevin Buzzard will discuss the future of mathematics and the role computers can play in proof development through tools such as Lean.Uploaded 02-10-25For more information go here: https://www.simonsfoundation.org/event/where-is-mathematics-going/ Sun, 11 Oct 2026 16:51:00 -0000 full Simons Foundation Where is Mathematics Going?~Is there a better way to do this? In this Presidential Lecture, Kevin Buzzard will discuss the future of mathematics and the role computers can play in proof development through tools such as Lean.Uploaded 02-10-25For more information go here: https://www.simonsfoundation.org/event/where-is-mathematics-going/ Where is Mathematics Going?
~
Is there a better way to do this? In this Presidential Lecture, Kevin Buzzard will discuss the future of mathematics and the role computers can play in proof development through tools such as Lean.

Uploaded 02-10-25

For more information go here: https://www.simonsfoundation.org/event/where-is-mathematics-going/

]]> 3333 no Observations of type Ia supernovae (SN Ia) ushered in a cosmological revolution: the expansion of the Universe is accelerating, driven by dark energy. I will describe current cosmological applications of SN Ia to measure the Hubble constant and constrain the nature of dark energy, with an emphasis on the limiting factors in these measurements. Some of these limits come from our lack of detailed understanding of the progenitors and explosion physics of SN Ia; I will review these open questions and their potential implications for current and future surveys. More details: https://www.simonsfoundation.org/event/2020-spring-cca-friday-colloquium-saurabh-jha/Uploaded 13-03-20 Sun, 11 Oct 2026 09:51:00 -0000 full Simons Foundation Observations of type Ia supernovae (SN Ia) ushered in a cosmological revolution: the expansion of the Universe is accelerating, driven by dark energy. I will describe current cosmological applications of SN Ia to measure the Hubble constant and constrain the nature of dark energy, with an emphasis on the limiting factors in these measurements. Some of these limits come from our lack of detailed understanding of the progenitors and explosion physics of SN Ia; I will review these open questions and their potential implications for current and future surveys. More details: https://www.simonsfoundation.org/event/2020-spring-cca-friday-colloquium-saurabh-jha/Uploaded 13-03-20 Observations of type Ia supernovae (SN Ia) ushered in a cosmological revolution: the expansion of the Universe is accelerating, driven by dark energy. I will describe current cosmological applications of SN Ia to measure the Hubble constant and constrain the nature of dark energy, with an emphasis on the limiting factors in these measurements. Some of these limits come from our lack of detailed understanding of the progenitors and explosion physics of SN Ia; I will review these open questions and their potential implications for current and future surveys. More details: https://www.simonsfoundation.org/event/2020-spring-cca-friday-colloquium-saurabh-jha/

Uploaded 13-03-20

]]> 4017 no Victor Wang will discuss some Diophantine counting problems for which an analysis via the circle method features the multiplicative statistics of an associated polynomial. Particular focus will be given to a Perazzo cubic fourfold, the subject of joint work in progress with Tim Browning and Ritabrata Munshi.Uploaded 25-09-25For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ Sun, 11 Oct 2026 02:51:00 -0000 full Simons Foundation Victor Wang will discuss some Diophantine counting problems for which an analysis via the circle method features the multiplicative statistics of an associated polynomial. Particular focus will be given to a Perazzo cubic fourfold, the subject of joint work in progress with Tim Browning and Ritabrata Munshi.Uploaded 25-09-25For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ Victor Wang will discuss some Diophantine counting problems for which an analysis via the circle method features the multiplicative statistics of an associated polynomial. Particular focus will be given to a Perazzo cubic fourfold, the subject of joint work in progress with Tim Browning and Ritabrata Munshi.

Uploaded 25-09-25

For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/

]]> 4096 no I will review the use of neutral hydrogen (HI) in the post reionization era as a tracer of the structure formation process. I will focus on atomic hydrogen both in absorption (IGM) and in emission (21cm intensity mapping). IGM is a probe of HI in volume, while intensity mapping is sensitive to the HI mass distribution. This combined information is thus highly complementary. The IGM, diffuse matter between galaxies (the so-called cosmic web) allows to measure the matter perturbations down to small scales and at high redshift. In recent years, baryonic acoustic oscillations have been detected at high redshift and unprecedented tight constraints on dark matter nature and neutrino mass have also been obtained, using IGM data (mainly from low-resolution BOSS and high-resolution quasar spectra from HIRES/Keck). On the other hand, emission at 21cm will probe is going to be an important probe that will also probe structure formation at high redshift. The IGM and intensity mapping can be used to address fundamental physical questions like the nature of dark matter, neutrino masses, possible extension of the standard cosmological model, and offer important clues on the cosmic cycle of baryons and the galaxy/IGM interplay. More details: https://www.simonsfoundation.org/event/2020-spring-cca-friday-colloquium-matteo-viel/Uploaded 13-03-20 Sat, 10 Oct 2026 19:51:00 -0000 full Simons Foundation I will review the use of neutral hydrogen (HI) in the post reionization era as a tracer of the structure formation process. I will focus on atomic hydrogen both in absorption (IGM) and in emission (21cm intensity mapping). IGM is a probe of HI in volume, while intensity mapping is sensitive to the HI mass distribution. This combined information is thus highly complementary. The IGM, diffuse matter between galaxies (the so-called cosmic web) allows to measure the matter perturbations down to small scales and at high redshift. In recent years, baryonic acoustic oscillations have been detected at high redshift and unprecedented tight constraints on dark matter nature and neutrino mass have also been obtained, using IGM data (mainly from low-resolution BOSS and high-resolution quasar spectra from HIRES/Keck). On the other hand, emission at 21cm will probe is going to be an important probe that will also probe structure formation at high redshift. The IGM and intensity mapping can be used to address fundamental physical questions like the nature of dark matter, neutrino masses, possible extension of the standard cosmological model, and offer important clues on the cosmic cycle of baryons and the galaxy/IGM interplay. More details: https://www.simonsfoundation.org/event/2020-spring-cca-friday-colloquium-matteo-viel/Uploaded 13-03-20 I will review the use of neutral hydrogen (HI) in the post reionization era as a tracer of the structure formation process. I will focus on atomic hydrogen both in absorption (IGM) and in emission (21cm intensity mapping). IGM is a probe of HI in volume, while intensity mapping is sensitive to the HI mass distribution. This combined information is thus highly complementary. The IGM, diffuse matter between galaxies (the so-called cosmic web) allows to measure the matter perturbations down to small scales and at high redshift. In recent years, baryonic acoustic oscillations have been detected at high redshift and unprecedented tight constraints on dark matter nature and neutrino mass have also been obtained, using IGM data (mainly from low-resolution BOSS and high-resolution quasar spectra from HIRES/Keck). On the other hand, emission at 21cm will probe is going to be an important probe that will also probe structure formation at high redshift. The IGM and intensity mapping can be used to address fundamental physical questions like the nature of dark matter, neutrino masses, possible extension of the standard cosmological model, and offer important clues on the cosmic cycle of baryons and the galaxy/IGM interplay. More details: https://www.simonsfoundation.org/event/2020-spring-cca-friday-colloquium-matteo-viel/

Uploaded 13-03-20

]]> 3734 no Distribution of Zeros, Eigenvalues and Eigenfunctions in Number Theory~We review some of the statistical laws that appear to govern zeta functions and automorphic forms, and in particular the extent to which they are observed numerically and their impact on extremal properties of arithmetical invariants.Uploaded 25-09-25For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ Sat, 10 Oct 2026 12:51:00 -0000 full Simons Foundation Distribution of Zeros, Eigenvalues and Eigenfunctions in Number Theory~We review some of the statistical laws that appear to govern zeta functions and automorphic forms, and in particular the extent to which they are observed numerically and their impact on extremal properties of arithmetical invariants.Uploaded 25-09-25For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ Distribution of Zeros, Eigenvalues and Eigenfunctions in Number Theory
~
We review some of the statistical laws that appear to govern zeta functions and automorphic forms, and in particular the extent to which they are observed numerically and their impact on extremal properties of arithmetical invariants.

Uploaded 25-09-25

For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/

]]> 4637 no The Gaia mission has provided distance and velocity measurements of over a billion stars in the Milky Way, making it the largest stellar catalog at hand. Simultaneously, recent developments in cosmological simulations have made it possible to track stars and dark matter in realistic Milky Way-like galaxies. In this talk, I will demonstrate how using cutting-edge simulations and Gaia data in tandem has enabled me to start building the first local map of the cold dark matter phase space distribution in our Galaxy. Doing so led me to discover Nyx, a stream of stars in the solar neighborhood that I identified using machine learning methods. Nyx, potentially the result of a prograde merger, is crucial in understanding the formation of the disk of the Milky Way as it might have been associated with an accreted dark disk. Finally, I will summarize how future surveys will help fully map out the phase space distribution of dark matter in the Milky Way, and show that such an empirical map will have extensive ramifications both for our understanding of the formation of the Milky Way, and for direct dark matter searches. More details: https://www.simonsfoundation.org/event/cca-special-seminar-lina-necib/Uploaded 13-03-20 Sat, 10 Oct 2026 05:51:00 -0000 full Simons Foundation The Gaia mission has provided distance and velocity measurements of over a billion stars in the Milky Way, making it the largest stellar catalog at hand. Simultaneously, recent developments in cosmological simulations have made it possible to track stars and dark matter in realistic Milky Way-like galaxies. In this talk, I will demonstrate how using cutting-edge simulations and Gaia data in tandem has enabled me to start building the first local map of the cold dark matter phase space distribution in our Galaxy. Doing so led me to discover Nyx, a stream of stars in the solar neighborhood that I identified using machine learning methods. Nyx, potentially the result of a prograde merger, is crucial in understanding the formation of the disk of the Milky Way as it might have been associated with an accreted dark disk. Finally, I will summarize how future surveys will help fully map out the phase space distribution of dark matter in the Milky Way, and show that such an empirical map will have extensive ramifications both for our understanding of the formation of the Milky Way, and for direct dark matter searches. More details: https://www.simonsfoundation.org/event/cca-special-seminar-lina-necib/Uploaded 13-03-20 The Gaia mission has provided distance and velocity measurements of over a billion stars in the Milky Way, making it the largest stellar catalog at hand. Simultaneously, recent developments in cosmological simulations have made it possible to track stars and dark matter in realistic Milky Way-like galaxies. In this talk, I will demonstrate how using cutting-edge simulations and Gaia data in tandem has enabled me to start building the first local map of the cold dark matter phase space distribution in our Galaxy. Doing so led me to discover Nyx, a stream of stars in the solar neighborhood that I identified using machine learning methods. Nyx, potentially the result of a prograde merger, is crucial in understanding the formation of the disk of the Milky Way as it might have been associated with an accreted dark disk. Finally, I will summarize how future surveys will help fully map out the phase space distribution of dark matter in the Milky Way, and show that such an empirical map will have extensive ramifications both for our understanding of the formation of the Milky Way, and for direct dark matter searches. More details: https://www.simonsfoundation.org/event/cca-special-seminar-lina-necib/

Uploaded 13-03-20

]]> 4035 no The conjectural distributions for class groups of number fields from the Cohen–Lenstra–Martinet heuristics are known to be universal distributions on abelian groups. We will discuss known results and open problems on the universality of distributions of groups, including non-abelian groups, modules, and other algebraic structures that arise in arithmetic statistics.Uploaded 25-09-25For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ Fri, 09 Oct 2026 22:51:00 -0000 full Simons Foundation The conjectural distributions for class groups of number fields from the Cohen–Lenstra–Martinet heuristics are known to be universal distributions on abelian groups. We will discuss known results and open problems on the universality of distributions of groups, including non-abelian groups, modules, and other algebraic structures that arise in arithmetic statistics.Uploaded 25-09-25For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ The conjectural distributions for class groups of number fields from the Cohen–Lenstra–Martinet heuristics are known to be universal distributions on abelian groups. We will discuss known results and open problems on the universality of distributions of groups, including non-abelian groups, modules, and other algebraic structures that arise in arithmetic statistics.

Uploaded 25-09-25

For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/

]]> 4162 no How different would our Universe look with the addition of extra particles and forces beyond what we know? We already have ample gravitational evidence for at least one invisible new particle that has properties unlike any particle we have previously discovered. It is possible that this dark matter is made of many different kinds of particles that experience forces unlike the ones we are familiar with in day-to-day life. If these forces only act on dark particles, it may be difficult to discover them and learn more about what is happening in this dark sector. However, dark matter and visible matter do interact gravitationally at the very minimum, and this fact alone might be a good reason not to lose hope. If there are dark forces affecting the distribution of dark matter in our Universe, then that distribution will gravitationally affect the visible matter that we can see. I will discuss how the gravitational portal between dark and visible matter can constrain dark matter theories where dark matter can dissipate energy, can scatter with itself (elastically or inelastically), or can be born non-thermally in the moments after the Big Bang. I will demonstrate this constraining power by harnessing synergies between astrophysical systems including stars, the local Milky Way, nearby dwarf galaxies, galaxy clusters, and large-scale cosmological structures. More details: https://www.simonsfoundation.org/event/cca-special-seminar-katelin-schulz/Uploaded 13-03-20 Fri, 09 Oct 2026 15:51:00 -0000 full Simons Foundation How different would our Universe look with the addition of extra particles and forces beyond what we know? We already have ample gravitational evidence for at least one invisible new particle that has properties unlike any particle we have previously discovered. It is possible that this dark matter is made of many different kinds of particles that experience forces unlike the ones we are familiar with in day-to-day life. If these forces only act on dark particles, it may be difficult to discover them and learn more about what is happening in this dark sector. However, dark matter and visible matter do interact gravitationally at the very minimum, and this fact alone might be a good reason not to lose hope. If there are dark forces affecting the distribution of dark matter in our Universe, then that distribution will gravitationally affect the visible matter that we can see. I will discuss how the gravitational portal between dark and visible matter can constrain dark matter theories where dark matter can dissipate energy, can scatter with itself (elastically or inelastically), or can be born non-thermally in the moments after the Big Bang. I will demonstrate this constraining power by harnessing synergies between astrophysical systems including stars, the local Milky Way, nearby dwarf galaxies, galaxy clusters, and large-scale cosmological structures. More details: https://www.simonsfoundation.org/event/cca-special-seminar-katelin-schulz/Uploaded 13-03-20 How different would our Universe look with the addition of extra particles and forces beyond what we know? We already have ample gravitational evidence for at least one invisible new particle that has properties unlike any particle we have previously discovered. It is possible that this dark matter is made of many different kinds of particles that experience forces unlike the ones we are familiar with in day-to-day life. If these forces only act on dark particles, it may be difficult to discover them and learn more about what is happening in this dark sector. However, dark matter and visible matter do interact gravitationally at the very minimum, and this fact alone might be a good reason not to lose hope. If there are dark forces affecting the distribution of dark matter in our Universe, then that distribution will gravitationally affect the visible matter that we can see. I will discuss how the gravitational portal between dark and visible matter can constrain dark matter theories where dark matter can dissipate energy, can scatter with itself (elastically or inelastically), or can be born non-thermally in the moments after the Big Bang. I will demonstrate this constraining power by harnessing synergies between astrophysical systems including stars, the local Milky Way, nearby dwarf galaxies, galaxy clusters, and large-scale cosmological structures. More details: https://www.simonsfoundation.org/event/cca-special-seminar-katelin-schulz/

Uploaded 13-03-20

]]> 3685 no We prove the simultaneous equidistribution conjecture of Michel and Venkatesh for the embedding of a torus into two distinct inner forms of PGL_2 assuming a o(1) strengthening of the non-existence of Siegel zeros for quadratic characters.Uploaded 25-09-25Since the number of such exceptional characters is essentially O(1) per dyadic interval, our approach improves the previous analytic approach of Blomer–Brumley and the ergodic Aka–Einsiedler–Shapira approach, which covers at best 99% discriminants in [X, 2X] due to a double splitting condition.The relevance of this topic to the workshop is that an essential tool in the proof are bounds for fractional moments of L-functions; in fact, we uncover a non-trivial intersection with the work of Harper on random multiplicative functions, but we end up not needing it at the end of the day for our specific application (although it would be needed for certain generalizations of our result).For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ Fri, 09 Oct 2026 08:51:00 -0000 full Simons Foundation We prove the simultaneous equidistribution conjecture of Michel and Venkatesh for the embedding of a torus into two distinct inner forms of PGL_2 assuming a o(1) strengthening of the non-existence of Siegel zeros for quadratic characters.Uploaded 25-09-25Since the number of such exceptional characters is essentially O(1) per dyadic interval, our approach improves the previous analytic approach of Blomer–Brumley and the ergodic Aka–Einsiedler–Shapira approach, which covers at best 99% discriminants in [X, 2X] due to a double splitting condition.The relevance of this topic to the workshop is that an essential tool in the proof are bounds for fractional moments of L-functions; in fact, we uncover a non-trivial intersection with the work of Harper on random multiplicative functions, but we end up not needing it at the end of the day for our specific application (although it would be needed for certain generalizations of our result).For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ We prove the simultaneous equidistribution conjecture of Michel and Venkatesh for the embedding of a torus into two distinct inner forms of PGL_2 assuming a o(1) strengthening of the non-existence of Siegel zeros for quadratic characters.

Uploaded 25-09-25

Since the number of such exceptional characters is essentially O(1) per dyadic interval, our approach improves the previous analytic approach of Blomer–Brumley and the ergodic Aka–Einsiedler–Shapira approach, which covers at best 99% discriminants in [X, 2X] due to a double splitting condition.

The relevance of this topic to the workshop is that an essential tool in the proof are bounds for fractional moments of L-functions; in fact, we uncover a non-trivial intersection with the work of Harper on random multiplicative functions, but we end up not needing it at the end of the day for our specific application (although it would be needed for certain generalizations of our result).

For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/

]]> 3714 no I will discuss how black holes can become nature's laboratories for new ultralight particles and ongoing observations of gravitational waves can inform models of particle physics. When a particle's Compton wavelength is comparable to the horizon size of a black hole, energy and angular momentum from the black hole are converted into exponentially growing clouds of bosons, creating a gravitational atom in the sky. Theories beyond the Standard Model often include new, light, feebly interacting particles -- including the QCD axion -- whose discovery requires novel observations and search strategies. I will show how previously open parameter space of axions which interact only gravitationally can be constrained by observations of rapidly spinning black holes. I will also show how such `gravitational atoms' may source up to thousands of monochromatic gravitational wave signals, and discuss my ongoing work to search for these signals in current data, enabling LIGO to discover or exclude new particles. More details: https://www.simonsfoundation.org/event/cca-special-seminar-masha-baryakhtar/Uploaded 13-03-20 Fri, 09 Oct 2026 01:51:00 -0000 full Simons Foundation I will discuss how black holes can become nature's laboratories for new ultralight particles and ongoing observations of gravitational waves can inform models of particle physics. When a particle's Compton wavelength is comparable to the horizon size of a black hole, energy and angular momentum from the black hole are converted into exponentially growing clouds of bosons, creating a gravitational atom in the sky. Theories beyond the Standard Model often include new, light, feebly interacting particles -- including the QCD axion -- whose discovery requires novel observations and search strategies. I will show how previously open parameter space of axions which interact only gravitationally can be constrained by observations of rapidly spinning black holes. I will also show how such `gravitational atoms' may source up to thousands of monochromatic gravitational wave signals, and discuss my ongoing work to search for these signals in current data, enabling LIGO to discover or exclude new particles. More details: https://www.simonsfoundation.org/event/cca-special-seminar-masha-baryakhtar/Uploaded 13-03-20 I will discuss how black holes can become nature's laboratories for new ultralight particles and ongoing observations of gravitational waves can inform models of particle physics. When a particle's Compton wavelength is comparable to the horizon size of a black hole, energy and angular momentum from the black hole are converted into exponentially growing clouds of bosons, creating a gravitational atom in the sky. Theories beyond the Standard Model often include new, light, feebly interacting particles -- including the QCD axion -- whose discovery requires novel observations and search strategies. I will show how previously open parameter space of axions which interact only gravitationally can be constrained by observations of rapidly spinning black holes. I will also show how such `gravitational atoms' may source up to thousands of monochromatic gravitational wave signals, and discuss my ongoing work to search for these signals in current data, enabling LIGO to discover or exclude new particles. More details: https://www.simonsfoundation.org/event/cca-special-seminar-masha-baryakhtar/

Uploaded 13-03-20

]]> 4106 no Jonathan Keating will discuss the evaluation of the joint moments of the characteristic polynomials of random unitary matrices and their derivatives, and in this context the joint moments of the Riemann zeta-function and its derivates, on the critical line. I also hope to discuss extensions to other symmetry classes.Uploaded 25-09-25For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ Thu, 08 Oct 2026 18:51:00 -0000 full Simons Foundation Jonathan Keating will discuss the evaluation of the joint moments of the characteristic polynomials of random unitary matrices and their derivatives, and in this context the joint moments of the Riemann zeta-function and its derivates, on the critical line. I also hope to discuss extensions to other symmetry classes.Uploaded 25-09-25For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ Jonathan Keating will discuss the evaluation of the joint moments of the characteristic polynomials of random unitary matrices and their derivatives, and in this context the joint moments of the Riemann zeta-function and its derivates, on the critical line. I also hope to discuss extensions to other symmetry classes.

Uploaded 25-09-25

For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/

]]> 3974 no As they orbit within a host galaxy like the Milky Way, tidally-disrupting satellite galaxies and star clusters produce streams of stars that nearly trace out the orbit of their progenitor system. These resulting stellar streams therefore provide otherwise unobservable information about the galactic force field and are one of the most promising tools for measuring the sub-galaxy-scale properties of dark matter. However, streams that form in more realistic galactic environments also record many other interesting dynamical phenomena, such as time-dependent perturbations from the Galactic bar and the gravitational influence of the Magellanic Clouds. I will show recent work on a few of the most prominent streams in the Milky Way that demonstrate that streams not only have the capacity to deliver precise constraints on the nature of dark matter, but are also sensitive to the physical processes at work during the assembly and evolution of our Galaxy. I will argue that, in order to deliver accurate and meaningful constraints on dark matter in either of these contexts, we must understand how these other complex–but interesting–effects may bias our inferences and conclusions from modeling individual streams. More details: https://www.simonsfoundation.org/event/cca-special-seminar-adrian-price-whelan/Uploaded 13-03-20 Thu, 08 Oct 2026 11:51:00 -0000 full Simons Foundation As they orbit within a host galaxy like the Milky Way, tidally-disrupting satellite galaxies and star clusters produce streams of stars that nearly trace out the orbit of their progenitor system. These resulting stellar streams therefore provide otherwise unobservable information about the galactic force field and are one of the most promising tools for measuring the sub-galaxy-scale properties of dark matter. However, streams that form in more realistic galactic environments also record many other interesting dynamical phenomena, such as time-dependent perturbations from the Galactic bar and the gravitational influence of the Magellanic Clouds. I will show recent work on a few of the most prominent streams in the Milky Way that demonstrate that streams not only have the capacity to deliver precise constraints on the nature of dark matter, but are also sensitive to the physical processes at work during the assembly and evolution of our Galaxy. I will argue that, in order to deliver accurate and meaningful constraints on dark matter in either of these contexts, we must understand how these other complex–but interesting–effects may bias our inferences and conclusions from modeling individual streams. More details: https://www.simonsfoundation.org/event/cca-special-seminar-adrian-price-whelan/Uploaded 13-03-20 As they orbit within a host galaxy like the Milky Way, tidally-disrupting satellite galaxies and star clusters produce streams of stars that nearly trace out the orbit of their progenitor system. These resulting stellar streams therefore provide otherwise unobservable information about the galactic force field and are one of the most promising tools for measuring the sub-galaxy-scale properties of dark matter. However, streams that form in more realistic galactic environments also record many other interesting dynamical phenomena, such as time-dependent perturbations from the Galactic bar and the gravitational influence of the Magellanic Clouds. I will show recent work on a few of the most prominent streams in the Milky Way that demonstrate that streams not only have the capacity to deliver precise constraints on the nature of dark matter, but are also sensitive to the physical processes at work during the assembly and evolution of our Galaxy. I will argue that, in order to deliver accurate and meaningful constraints on dark matter in either of these contexts, we must understand how these other complex–but interesting–effects may bias our inferences and conclusions from modeling individual streams. More details: https://www.simonsfoundation.org/event/cca-special-seminar-adrian-price-whelan/

Uploaded 13-03-20

]]> 3775 no The Square of the Riemann Zeta Function Gives Rise to Critical Multiplicative Chaos~Multiplicative chaos is a class of random measures that have recently been found to have strong connections with number theoretic objects like L-functions and character sums and the phenomenon of “better than square-root cancellation.” Saksman and Webb have conjectured that integrating test functions against absolute powers of the Riemann zeta function should give rise to these measures. The square of the zeta function is particularly interesting, since this should correspond to the so-called critical chaos. Adam Harper will report on joint work (in preparation) with Saksman and Webb, which proves their conjecture for zeta squared. Harper will try to give a gentle introduction to these problems, and indicate some of the main proof ideas, which may be of independent interest.Uploaded 25-09-25For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ Thu, 08 Oct 2026 04:51:00 -0000 full Simons Foundation The Square of the Riemann Zeta Function Gives Rise to Critical Multiplicative Chaos~Multiplicative chaos is a class of random measures that have recently been found to have strong connections with number theoretic objects like L-functions and character sums and the phenomenon of “better than square-root cancellation.” Saksman and Webb have conjectured that integrating test functions against absolute powers of the Riemann zeta function should give rise to these measures. The square of the zeta function is particularly interesting, since this should correspond to the so-called critical chaos. Adam Harper will report on joint work (in preparation) with Saksman and Webb, which proves their conjecture for zeta squared. Harper will try to give a gentle introduction to these problems, and indicate some of the main proof ideas, which may be of independent interest.Uploaded 25-09-25For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/ The Square of the Riemann Zeta Function Gives Rise to Critical Multiplicative Chaos
~
Multiplicative chaos is a class of random measures that have recently been found to have strong connections with number theoretic objects like L-functions and character sums and the phenomenon of “better than square-root cancellation.” Saksman and Webb have conjectured that integrating test functions against absolute powers of the Riemann zeta function should give rise to these measures. The square of the zeta function is particularly interesting, since this should correspond to the so-called critical chaos. Adam Harper will report on joint work (in preparation) with Saksman and Webb, which proves their conjecture for zeta squared. Harper will try to give a gentle introduction to these problems, and indicate some of the main proof ideas, which may be of independent interest.

Uploaded 25-09-25

For more information go here: https://www.simonsfoundation.org/event/mps-conference-on-universal-statistics-in-number-theory/

]]> 4114 no More details: https://www.simonsfoundation.org/event/quantum-matter-computation-meets-experiments/Uploaded 24-03-20 Wed, 07 Oct 2026 21:51:00 -0000 full Simons Foundation More details: https://www.simonsfoundation.org/event/quantum-matter-computation-meets-experiments/Uploaded 24-03-20 More details: https://www.simonsfoundation.org/event/quantum-matter-computation-meets-experiments/

Uploaded 24-03-20

]]> 2524 no