On C*-completions of discrete (quantum) group rings

Date

Apr 4, 2019

Time

1:30 PM - 2:30 PM

Speaker

Adam Skalski

Affiliation

Warschau

Language

en

Main Topic

Mathematik

Other Topics

Mathematik

Host

Prof. Dr. U. Krähmer

Description

To any discrete group one can associate its complex group ring, which is a unital *-algebra. We will investigate when this algebra admits a unique C*-completion (in other words, all its embeddings into a *-algebra of bounded operators on a Hilbert space yield the same norm). Grigorchuk, Musat and Rordam observed this happens when the group in question is locally finite and asked if this is the only case. We will discuss what is known about their question and show that in the quantum world, i.e. when we look at C*-completions of Hopf*-algebras associated to compact quantum groups, the answer is negative. Based on the joint work with Martijn Caspers.

Links

• Seminar Algebra, Geometrie und Kombinatorik

Last modified: Mar 25, 2019, 10:32:26 AM