10:00 – 11:00 Tattwamasi Amrutam (Polish Academy of Sciences)
Title: Invariant subalgebras of reduced group C*-algebras associated with negatively curved groups
Abstract: Let G be a countable discrete group. Associated with it is the reduced group C*-algebra $C*_r(G). It is interesting to ask which group properties are reflected at the group von Neumann algebra or reduced group C*-algebra level. We say that G has C*-invariant subalgebra rigidity property (C*-ISR property) if every G-invariant-C*-subalgebra is of the form C*_r(N) for some normal subgroup N.
In this talk, we shall show that there is a significant class of groups that satisfy the C*-ISR-property, including all torsion-free non-amenable acylindrically hyperbolic groups and a finite product of such groups. We shall also discuss the implications for infinite groups satisfying the -ISR property in that they are either C*-simple or simple amenable.
This is a joint work with Yongle Jiang.
**********
11:15 – 12:15 Bhishan Jacelon (Czech Academy of Sciences)
Title: Tracially lyriform C*-algebras
Abstract: I will discuss a recent paper that develops a unified theory of metrics on tracial state spaces and studies the geometry and statistics of embedding spaces associated with certain classifiable C*-algebras.
**********
14:00 – 15:00 Mario Klisse (Christian-Albrechts-Universität Kiel)
Title: Simplicity of Right-Angled Hecke C*-Algebras
Abstract: Iwahori–Hecke algebras are deformations of group algebras associated with Coxeter groups, depending on a multi-parameter. They admit a natural representation on the ℓ²-space of the underlying group and therefore give rise to C*-algebras and von Neumann algebras via completion. In this talk, I will explain how properties of certain combinatorial boundaries can be used to obtain a complete characterization of the simplicity of right-angled Hecke C*-algebras. Time permitting, I will also discuss extensions of these results to the setting of reduced graph products of general C*-algebras.
