Non Kazhdan's groups and a new approximation property for tracial von Neumann algebras

Paul Jolissaint

doi:10.36045/j.bbms.250227

paper

Non Kazhdan's groups and a new approximation property for tracial von Neumann algebras

arXiv:2410.06579 · doi:10.36045/j.bbms.250227

Abstract

We define a new approximation property for tracial von Neumann algebras, called \textit{weakly mixing approximation property} which, for discrete groups and II $_{1}$ factors, is equivalent to the negation of Kazhdan's property (T).

Final version, accepted for publication in Bulletin of the Belgian Mathematical Society - Simon Stevin, 20 pages