Thu, 05 Dec 2013

16:00 - 17:00
L2

Random matrices and the asymptotic behavior of the zeros of the Taylor approximants of the exponential function

Ken McLaughlin
(University of Arizona)
Abstract

The plan: start with an introduction to several random matrix ensembles and discuss asymptotic properties of the eigenvalues of the matrices, the last one being the so-called "Normal Matrix Model", and the connection described in the title will be explained. If all goes well I will end with an explanation of asymptotic computations for a new normal matrix model example, which demonstrates a form of universality.

(NOTE CHANGE OF VENUE TO L2)

Fri, 07 Jun 2013
16:30
L2

Langlands functoriality and non linear Poisson formulas

Professor Laurent Lafforgue
(IHES)
Abstract

"We introduce some type of generalized Poisson formula which is equivalent 
to Langlands' automorphic transfer from an arbitrary reductive group over a 
global field to a general linear group."

Mon, 29 Apr 2013
16:30
L2

Systemic Risk

George Papanicolaou
(Stanford University)
Abstract

The quantification and management of risk in financial markets
is at the center of modern financial mathematics. But until recently, risk
assessment models did not consider the effects of inter-connectedness of
financial agents and the way risk diversification impacts the stability of
markets. I will give an introduction to these problems and discuss the
implications of some mathematical models for dealing with them. 

Tue, 26 Feb 2013
17:00
L2

Relatively hyperbolic groups, mapping class groups and random walks

Alessandro Sisto
(Oxford)
Abstract

I will discuss similarities and differences between the geometry of
relatively hyperbolic groups and that of mapping class groups.
I will then discuss results about random walks on such groups that can
be proven using their common geometric features, namely the facts that
generic elements of (non-trivial) relatively hyperbolic groups are
hyperbolic, generic elements in mapping class groups are pseudo-Anosovs
and random paths of length $n$ stay $O(\log(n))$-close to geodesics in
(non-trivial) relatively hyperbolic groups and
$O(\sqrt{n}\log(n))$-close to geodesics in mapping class groups.

Thu, 21 Feb 2013

15:30 - 16:30
L2

Centers and traces of categorified affine Hecke algebras (or, some tricks with coherent complexes on the Steinberg variety)

Anatoly Preygel
(UC Berkeley)
Abstract

The bounded coherent dg-category on (suitable versions of) the Steinberg stack of a reductive group G is a categorification of the affine Hecke algebra in representation theory.  We discuss how to describe the center and universal trace of this monoidal dg-category.  Many of the techniques involved are very general, and the description makes use of the notion of "odd micro-support" of coherent complexes.  This is joint work with Ben-Zvi and Nadler.

Tue, 05 Mar 2013
17:00
L2

"Galois problems in Schubert Calculus, and related problems"

Prof Iain Gordon
(Edinburgh)
Abstract

I will discuss some recent developments in Schubert calculus and a potential relation to classical combinatorics for symmetric groups and possible extensions to complex reflection groups.

Tue, 12 Feb 2013
17:00
L2

Rigidity of group actions

Alex Gorodnik
(Bristol)
Abstract

We discuss the problem to what extend a group action determines geometry of the space. 
More precisely, we show that for a large class of actions measurable isomorphisms must preserve 
the geometric structure as well. This is a joint work with Bader, Furman, and Weiss.

Tue, 29 Jan 2013
17:00
L2

Intersections of subgroups of free products.

Yago Antolin Pichel
(Southampton)
Abstract

I will introduce the notion of Kurosh rank for subgroups of 
free products. This rank satisfies the Howson property, i.e. the 
intersection of two subgroups of finite Kurosh rank has finite Kurosh rank.
I will present a version of the Strengthened Hanna Neumann inequality in 
the case of free products of right-orderable groups. Joint work with  A. 
Martino and I. Schwabrow.

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