Tue, 03 Mar 2026
16:00
C3

Rigidity for graph product von Neumann algebras

Camille Horbez
(Université Paris-Saclay)
Abstract

Graph products of groups were introduced by Green as a construction that encompasses both direct products and free products. Likewise, the notion of graph product of von Neumann algebras, introduced by Caspers and Fima, recovers both tensor products and free products. Camille Horbez will present rigidity theorems for graph products of tracial von Neumann algebras, and discuss the computation of their symmetries, drawing parallels with the case of groups. This is a joint work with Adrian Ioana. 

Tue, 24 Feb 2026
17:00
C3

AF-embeddability of decomposition rank 1 algebras.

Joachim Zacharias
(University of Glasgow)
Abstract

AF-embeddability, i.e., the question whether a given C*-algebra can be realised as a subalgebra of an AF-algebra, has been studied for a long time with prominent early results by Pimsner and Voicuescu who constructed such embeddings for irrational rotation algebras in 1980. Since then, many AF-embeddings have been constructed for concrete examples but also many non-constructive AF-embeddability results have been obtained for classes of algebras typically assuming the UCT. 

In this talk by Joachim Zacharias, we will consider a separable unital C*-algebra A of decomposition rank at most 1 and construct from a suitable system of 1-decomposable cpc-approximations an AF-algebra E together with an embedding of A into E and a conditional expectation of E onto A without assuming the UCT. We also consider some extensions of this inclusion and indicate some applications.

Tue, 17 Feb 2026
16:00
C3

Dualities and Extremal Inequalities in Convex Geometry

Kasia Wyczesany
(Leeds University)
Abstract

Convex geometry has long been influenced by the study of dualities and extremal inequalities, with origins in classical affine geometry and functional analysis. In this talk, Kasia Wyczesany will explore an abstract concept of duality, focusing on the classical idea of the polar set, which captures the duality of finite-dimensional normed spaces. This notion leads to fundamental questions about volume products, inspiring some of the most famous inequalities in the field. Whilst Mahler’s influential 1939 conjecture regarding the minimiser of the volume product will be mentioned, the emphasis will be on the Blaschke–Santaló inequality, which identifies the maximiser, along with its modern extensions. Main new results are joint work with S. Artstein-Avidan and S. Sadovsky, and S. Artstein-Avidan and M. Fradelizi. 

Out-of-equilibrium full counting statistics in Gaussian theories of quantum magnets
Senese, R Robertson, J Essler, F SciPost Physics (20 Nov 2024)

The café will close for the Christmas break on Tuesday, 23 December at 2:00 pm and will reopen as usual on Monday, 5 January. 

The café team would like to take this opportunity to wish all their customers a Merry Christmas and a Happy New Year.

 

The Vice-Chancellor’s Awards 2026 are now open for nominations. There are loads of categories so we are all eligible. This year’s awards include a number of new and amended categories, with the ceremony to be held at the Schwarzman building (so not far to travel when you win).

More information about the awards

When you put a mic on a ruler (we couldn't find a set square) and give it to three of our Mirzakhani students...

Selfie, selfie, it's your call, who's the fairest of them all?

Sam Howison, obviously. Except for one thing.

Subscribe to