English

A nonseparable amenable operator algebra which is not isomorphic to a C*-algebra

Operator Algebras 2014-03-17 v5 Logic

Abstract

It has been a longstanding problem whether every amenable operator algebra is isomorphic to a (necessarily nuclear) C*-algebra. In this note, we give a nonseparable counterexample. The existence of a separable counterexample remains an open problem. We also initiate a general study of unitarizability of representations of amenable groups in C*-algebras and show that our method cannot produce a separable counterexample.

Keywords

Cite

@article{arxiv.1309.2145,
  title  = {A nonseparable amenable operator algebra which is not isomorphic to a C*-algebra},
  author = {Yemon Choi and Ilijas Farah and Narutaka Ozawa},
  journal= {arXiv preprint arXiv:1309.2145},
  year   = {2014}
}

Comments

Some improvements

R2 v1 2026-06-22T01:23:21.605Z