Please note that the list below only shows forthcoming events, which may not include regular events that have not yet been entered for the forthcoming term. Please see the past events page for a list of all seminar series that the department has on offer.

 

Past events in this series


Tue, 24 Feb 2026
16:00
L6

Random Matrices and Free Cumulants

Roland Speicher
Abstract

The asymptotic large N limit of random matrices often transforms classical concepts (independence, cumulants, partitions of sets) into their free counter-parts (free independence, free cumulants, non-crossing partitions) and the limit of random matrices gives rise to interesting operator algebras. I will explain these relations, with a particular emphasis on the effect of non-linear functions on the entries of random matrices

Tue, 03 Mar 2026
16:00
L6

The hyperbolic lattice point problem

Stephen Lester
Abstract
In this talk I will discuss the hyperbolic circle problem for $SL_2(\mathbb Z)$. Given two points $z, w$ that lie in the hyperbolic upper half‑plane, the problem is to determine the number of $SL_2(\mathbb Z)$ translates of w that lie in the hyperbolic disk centred at z with radius $arcosh(R/2)$ for large $R$. Selberg proved that the error term in this problem is $O(R^{2/3})$. I will describe some recent work in which we improve the error term to $o(R^{2/3})$ as $R$ tends to infinity, for $z,w$ that are CM-points of different, square-free discriminants. This is joint work with Dimitrios Chatzakos, Giacomo Cherubini, and Morten Risager.