Speaker: Miho Mukohara (Univ. Tokyo)
Title: C*-simplicity of relative profinite completions of generalized Baumslag-Solitar groups
Time/Date: 4:45-6:15pm, January 18 (Tue.), 2022
Room: This will be an online seminar on Zoom. Please ask Kawahigashi for the Zoom link.
Abstract: Locally compact groups are called C*-simple if their reduced group C*-algebras are simple. C*-simplicity of discrete groups has long been studied, and as of today, many characterizations have been found. On the other hand, C*-simplicity of non-discrete locally compact groups is not well understood compared to that of discrete groups. Suzuki recently gave constructions of non-discrete examples of locally compact C*-simple groups and Raum showed C*-simplicity of relative profinite completions of Baumslag-Solitar groups by using Suzuki's results. In this talk, I will explain a proof of C*-simplicity of relative profinite completions of generalized Baumslag-Solitar groups by using an analogue of the Powers averaging property.