Every countable group admits amenable actions on stably finite simple C*-algebras

Abstract

We give the first examples of (non-amenable group) amenable actions on stably finite simple C*-algebras. More precisely, we give such actions for any countable group in an explicit way. The main ingredients of our construction are the full Fock space of the regular representation and a trace-scaling automorphism.

arXiv commentMinor revisions based on referee report, 8 pages, to appear in American Journal of Mathematics