Previous Conferences & Workshops

Dec
08
2015

Computer Science/Discrete Mathematics Seminar II

Ramanujan coverings of graphs
Doron Puder
10:30am|West Bldg. Lect. Hall

Ramanujan graphs are optimal expander graphs, and their existence and construction have been the focus of much research during the last three decades. We prove that every bipartite Ramanujan graph has a $d$-covering which is also Ramanujan. This...

Dec
08
2015

Workshop on Flows, Foliations and Contact Structures

Quasigeodesic pseudo-Anosov flows in hyperbolic 3-manifolds
Sergio Fenley
10:00am|Simonyi Hall 101
We obtain a simple topological and dynamical systems condition which is necessary and sufficient for an arbitrary pseudo-Anosov flow in a closed, hyperbolic three manifold to be quasigeodesic. Quasigeodesic means that orbits are efficient in...
Dec
07
2015

Workshop on Flows, Foliations and Contact Structures

Tight, non-fillable contact structures on 3-manifolds
Andy Wand
4:00pm|Simonyi Hall 101
The modern development of contact geometry in 3 dimensions has seen several (due to Giroux, Wendl, Latschev and Wendl, Hutchings, and others) invariants of contact structures meant in some sense to measure non-(Stein /symplectic)-fillability of the...
Dec
07
2015

Workshop on Flows, Foliations and Contact Structures

Positive-definite symplectic four-manifolds
Jennifer Hom
2:30pm|Simonyi Hall 101
We give new constraints on the topology of symplectic four-manifolds using invariants from Heegaard Floer homology. In particular, we will prove that certain simply-connected four-manifolds with positive-definite intersection forms cannot admit...
Dec
07
2015

Members’ Seminar

No seminar today due to Workshop
No seminar today due to Workshop
2:00pm|S-101
Dec
07
2015

Workshop on Flows, Foliations and Contact Structures

Contact Structures, foliations and group actions
Jonathan Bowdan
11:30am|Simonyi Hall 101
We use contact deformations to study the topology of the space of taut foliations and group actions on the circle.
Dec
07
2015

Computer Science/Discrete Mathematics Seminar I

Bias vs low rank of polynomials with applications to list decoding and effective algebraic geometry
Abhishek Bhowmick
11:15am|West Bldg. Lect. Hall

Let $f$ be a polynomial of degree $d$ in $n$ variables over a finite field $\mathbb{F}$. The polynomial is said to be unbiased if the distribution of $f(x)$ for a uniform input $x \in \mathbb{F}^n$ is close to the uniform distribution over $\mathbb...

Dec
07
2015

Workshop on Flows, Foliations and Contact Structures

Floer homology, group orders, and taut foliations of hyperbolic 3-manifolds
Nathan Dunfeld
10:00am|Simonyi Hall 101
A bold conjecture of Boyer-Gorden-Watson and others posit that for any irreducible rational homology 3-sphere M the following three conditions are equivalent: (1) the fundamental group of M is left-orderable, (2) M has non-minimal Heegaard Floer...
Dec
07
2015

Workshop on Flows, Foliations and Contact Structures

8:00am

This workshop was part of the topical program "Geometric Structures on 3-Manifolds" which took place during the 2015-2016 academic year at the Institute for Advanced Study. The workshop focused on the relations between flows, 2-dimensional...

Dec
04
2015

Joint IAS/Princeton University Number Theory Seminar

Arithmetic of double torus quotients and the distribution of periodic torus orbits
Ilya Khayutin
2:45pm

In this talk I will describe some new arithmetic invariants for pairs of torus orbits on inner forms of $\mathbf{PGL}_n$ and $\mathbf{SL}_n$. These invariants allow us to significantly strengthen results towards the equidistribution of packets of...