Previous Conferences & Workshops

Nov
10
2021

Mathematical Conversations

Stochastic Characteristics: ellipticity and hypoellipticity from finite to infinite dimensions
Jonathan Mattingly
6:00pm|Birch Garden, Simons Hall

I will give an elementary introduction to the connections between diffusions and stochastic characteristics in $\mathbb R^n$. I will then explain how one might think about what it means to be elliptic or hypoellipticity in an infinite dimensional...

Nov
10
2021

Special Seminar

Random forests and hyperbolic symmetry
Roland Bauerschmidt
4:30pm|Simonyi Hall 101 and Remote Access

Given a finite graph, the arboreal gas is the measure on forests (subgraphs without cycles) in which each edge is weighted by a parameter $\beta>0$. Equivalently this model is bond percolation conditioned to be a forest, the independent sets of the...

Nov
10
2021

Arithmetic Groups

The congruence subgroup property for SL(2,Z)
William Yun Chen
11:00am|Simonyi 101 and Remote Access

Somehow, despite the title, $SL(2,Z)$ is the poster child for arithmetic groups not satisfying the congruence subgroup property, which is to say that it has finite index subgroups which can not be defined by congruence conditions on their...

Nov
10
2021

Character Varieties, Dynamics and Arithmetic

Dynamics on character varieties
William Goldman
10:00am|Simonyi Hall 101 and Remote Access

In these two talks, I will describe how the classification of locally homogeneous geometric structures (closely related to flat connections) leads to interesting dynamical systems.

Many interesting dynamical systems arise from the classification of...

Nov
09
2021

Seminar in Analysis and Geometry

3D Navier-Stokes equations: the dynamics of a blow-up
Alexey P Cheskidov
2:00pm|Simonyi Hall 101 and Remote Access

I will present an elementary introduction to the regularity/uniqueness issues for the Navier-Stokes equations. Thanks to the convex integration technique, the h-principle is starting to take shape for the uniqueness problem. It might be possible...

Nov
09
2021

Computer Science/Discrete Mathematics Seminar II

Introduction to Continuous Combinatorics II: semantic limits
Leonardo Coregliano
10:30am|Simonyi Hall 101 and Remote Access

The field of continuous combinatorics studies large (dense) combinatorial structures by encoding them in a "continuous" limit object, which is amenable to tools from analysis, topology, measure theory, etc. While the syntactic/algebraic approach of...

Nov
08
2021

Joint IAS/Princeton University Symplectic Geometry Seminar

Lagrangian Cobordisms and Enriched Knot Diagrams
Ipsita Datta
4:00pm|Fine Hall 314, Princeton University
We present some obstructions to the existence of Lagrangian cobordisms in $\mathbb R^4$. The obstructions arise from studying moduli spaces of holomorphic disks with corners with boundaries on immersed objects called Lagrangian tangles. The...
Nov
08
2021

Members' Colloquium

Which manifolds are symplectic?
Yakov Eliashberg
2:00pm|Simonyi Hall 101 and Remote Access

The question in the title was one of the founding questions in symplectic topology 40 years ago, and despite a lot of progress since that time, it remains widely open. In the talk I will discuss the initial questions, the progress, and the remaining...

Nov
08
2021

Computer Science/Discrete Mathematics Seminar I

The Kakeya Set conjecture over Z mod N for general N
Manik Dhar
11:15am|Simonyi Hall 101 and Remote Access

A Kakeya Set in (Z/N Z)^n is a set that contains a line in every direction.  It has been known for over a decade that such sets must be large when N is prime (or more generally over any finite field).  This goes back to Dvir's proof of the finite...