Previous Conferences & Workshops

Dec
15
2021

Lectures in Analysis and Geometry

The Ruelle invariant and convexity II
Julian Chaidez
2:00pm|Simonyi Hall 101 and Remote Access

In this talk, I will explain how the Ruelle invariant of a symplectomorphism and the Ruelle invariant of a Reeb flow are related via the open book construction. As an application, I will construct examples of Reeb flows on the sphere that are...

Dec
15
2021

Special Lecture

Can you hear the will of the people in the vote? The mathematics and policy of quantifying gerrymandering
Jonathan Mattingly
12:00pm|Dilworth Room

The US political system is built on representatives chosen by geographically localized regions. This presents the government with the problem of designing these districts. Every ten years, the US census counts the population and new political...

Dec
15
2021

Arithmetic Groups

Commutators in SL_2 and Markoff Surfaces
Chen Meiri
11:00am|Simonyi 101 and Remote Access

We discuss a local to global profinite principle for being a commutator in some arithmetic groups. Specifically we show that $SL_2(Z)$ satisfies such a principle, while it can fail with infinitely many exceptions for $SL_2(Z[1/p])$. The source of...

Dec
15
2021

Character Varieties, Dynamics and Arithmetic

The dynamics of Aut(Fn) actions on group presentations and representations
Alexander Lubotzky
10:00am|Simonyi Hall 101 and Remote Access

Several different areas of group theory, topology, and geometry have led to the study of the action of $Aut(Fn)$—the automorphism group of the free group on $n$ generators—on $Hom(Fn, G)$ when $G$ is either finite, compact or a simple Lie group. We...

Dec
14
2021

Seminar in Analysis and Geometry

Floer homology of Hamiltonians supported on subsets
Shira Tanny
2:00pm|Simonyi Hall 101 and Remote Access

Floer homology is a fundamental construction relating dynamical properties of Hamiltonian flows on symplectic manifolds to the topology of the manifold. Although this construction is global in nature, when the Hamiltonian flow is supported on a...

Dec
14
2021

Computer Science/Discrete Mathematics Seminar II

An Introduction to Lifted Expander Graphs
Fernando Granha Jeronimo
10:30am|Simonyi Hall 101 and Remote Access

Expander graphs are sparse and yet well-connected graphs. Several applications in theoretical computer science require explicit constructions of expander graphs, sometimes even with additional structure. One approach to their construction is to...

Dec
13
2021

Joint IAS/Princeton University Symplectic Geometry Seminar

Localization and flexibilization in symplectic geometry
Oleg Lazarev
4:00pm|Simonyi Hall 101

Localization is an important construction in algebra and topology that allows one to study global phenomena a single prime at a time. Flexibilization is an operation in symplectic topology introduced by Cieliebak and Eliashberg that makes any two...

Dec
13
2021

Members' Colloquium

A new random model for the Euler and Navier-Stokes equations and related equations
Jonathan Mattingly
2:00pm|Simonyi Hall 101 and Remote Access

I will introduce a new model of randomly agitated equations. I will focus on the finite finite dimensional approximations (analogous to Galerkin approximations) and the two-dimensional setting. I will discuss number of properties of the models...