English

Non-K-exact uniform Roe C*-algebras

Operator Algebras 2009-07-15 v1

Abstract

We prove that uniform Roe C*-algebras associated to some expander graphs coming from discrete groups with property (\tau) are not K-exact. In particular, we show that this is the case for the expander obtained as Cayley graphs of a sequence of alternating groups (with appropriately chosen generating sets).

Keywords

Cite

@article{arxiv.0907.2249,
  title  = {Non-K-exact uniform Roe C*-algebras},
  author = {Jan Spakula},
  journal= {arXiv preprint arXiv:0907.2249},
  year   = {2009}
}
R2 v1 2026-06-21T13:24:31.400Z