2019
Dec
16

# Eventss

2019
Dec
26

# (cancelled)

10:00am to 11:00am

2019
Dec
24

# Dor Elimelech (BGU) Restricted permutations and perfect matchings

2:30pm to 3:30pm

Abstract:

A restricted permutation of a locally finite directed graph $G=(V,E)$ is a vertex permutation $\pi: V\to V$ for which $(v,\pi(v))\in E$, for any vertex $v\in V$. The set of such permutations, denoted by $\Omega(G)$, with a group action induced from a subset of graph isomorphisms form a topological dynamical system. In the particular case presented by Schmidt and Strasser (2016), where $V=\mathbb{Z}^d$ and $(n,m)\in E$ iff $(n-m)\in A$ ($A\subseteq \mathbb{Z^d}$ is fixed), $\Omega(G)$ is a subshift of finite type.

A restricted permutation of a locally finite directed graph $G=(V,E)$ is a vertex permutation $\pi: V\to V$ for which $(v,\pi(v))\in E$, for any vertex $v\in V$. The set of such permutations, denoted by $\Omega(G)$, with a group action induced from a subset of graph isomorphisms form a topological dynamical system. In the particular case presented by Schmidt and Strasser (2016), where $V=\mathbb{Z}^d$ and $(n,m)\in E$ iff $(n-m)\in A$ ($A\subseteq \mathbb{Z^d}$ is fixed), $\Omega(G)$ is a subshift of finite type.

2020
Jan
15

# Analysis Seminar Dvoretsky Lecture: Sylvia Serfaty (NYU Courant) - Mean Field Limits for Coulomb Dynamics

12:00pm to 1:00pm

## Location:

Ross 70

We consider a system of N points evolving according to the gradient flow of their Coulomb or Riesz interaction, or a similar conservative flow. By Riesz interaction, we mean inverse power s of the distance with s between d-2 and d where d denotes the dimension. We show a convergence result as N tends to infinity to the expected limiting evolution equation. This was previously an open question in general dimension, rendered difficult by the singular nature of the interaction. We will also discuss briefly similar results in the context of models of superfluidity and superconductivity.

2019
Dec
17

# Nishant Chandgotia (HUJI), Predictive sets.

2:00pm to 3:00pm

## Location:

Ross 70

Abstract: A subset of the integers P is called predictive if for all zero-entropy processes X_i; i in Z, X_0 can be determined by X_i; i in P. The classical formula for entropy shows that the set of natural numbers forms a predictive set. In joint work with Benjamin Weiss, we will explore some necessary and some sufficient conditions for a set to be predictive. These sets are related to Riesz sets (as defined by Y. Meyer) which arise in the study of singular measures. This and several questions will be discussed during the talk.

2020
Jan
07

# Dmitry Dolgopyat (Maryland) On mixing properties of infinite measure preserving systems

2:00pm to 3:00pm

**Abstract:**We present several new results concerning mixing properties of

hyperbolic systems preserving an infinite measure making a particular

emphasis on mixing for extended systems. This talk is based on a joint

work with Peter Nandori.

2020
Jan
16

# Dvoretzky Lectures: Systems of points with Coulomb interactions

## Lecturer:

Sylvia Serfaty

2:30pm to 4:30pm

## Location:

Manchester House, Lecture Hall 2

Large ensembles of points with Coulomb interactions arise in various settings of condensed matter physics, classical and quantum mechanics, statistical mechanics, random matrices and even approximation theory, and they give rise to a variety of questions pertaining to analysis, Partial Differential Equations and probability.We will first review these motivations, then present the ''mean-field'' derivation of effective models and equations describing the system at the macroscopic scale.

2020
Jan
15

# Dvoretzky Lectures: Mean Field Limits for Coulomb Dynamics

## Lecturer:

Sylvia Serfaty

12:00pm to 2:00pm

## Location:

Ross 70

We consider a system of N points evolving according to the gradient flow of their Coulomb or Riesz interaction, or a similar conservative flow. By Riesz interaction, we mean inverse power s of the distance with s between d-2 and d where d denotes the dimension. We show a convergence result as N tends to infinity to the expected limiting evolution equation. This was previously an open question in general dimension, rendered difficult by the singular nature of the interaction. We will also discuss briefly similar results in the context of models of superfluidity and superconductivity.

2019
Nov
21

2020
Jan
15

# Dvoretzky Lectures 2020: Sylvia Serfaty (Courant Institute of Mathematical Sciences)

## Lecturer:

Prof. Sylvia Serfaty (Courant Institute of Mathematical Sciences)

Wed, 15/01/2020 - 12:00 to Thu, 16/01/2020 - 16:00

# Dvoretzky Lectures 2020: Sylvia Serfaty (Courant Institute of Mathematical Sciences)

2019
Nov
20

# Logic Seminar - Christian d'Elbée

11:00am to 1:00pm

## Location:

Ross building - Room 63

**Christian d'Elbée**will speak about generic generic abelian varieties.

**Generic**

**generic**

**abelian varieties.**

__Abstract:__

I will present work in progress in a new NSOP1 nonsimple theory: the expansion of an abelian variety by a generic subgroup, under some conditions on the endomorphism ring.

2019
Nov
24

# Game Theory Seminar: Naftali Tishby "Information Theory of Deep Learning"

2:00pm to 3:00pm

## Location:

Elath Hall, 2nd floor, Feldman Building

In the past several years we have developed a comprehensive theory of large scale learning with Deep Neural Networks (DNN), when optimized with Stochastic Gradient Decent (SGD). Read more about Game Theory Seminar: Naftali Tishby "Information Theory of Deep Learning"

2020
Feb
04

# (no talk)

12:00pm to 1:00pm

2019
Nov
28

# Konstantin Golubev (ETH) - On non-autocorrelated functions on a hyperbolic surface

10:00am to 11:00am

## Location:

Ross 70

An L^2-function on a finite volume hyperbolic surface is called non-autocorrelated if it is perpendicular to its image under A_r, the operator of averaging over the circle of radius r, where r is fixed. We show that the support of such a function is small, namely, it takes not more than (r+1) / exp(r/2) of the volume of the surface. In my talk, I'll prove this result, and show its connection to the equidistribution of the circle on a surface (proved by Nevo).