English

Fundamental group of simple $C^*$-algebras with unique trace II

Operator Algebras 2010-06-23 v2 Functional Analysis

Abstract

We show that any countable subgroup of the multiplicative group R+×\mathbb{R}_+^{\times} of positive real numbers can be realized as the fundamental group F(A)\mathcal{F}(A) of a separable simple unital CC^*-algebra AA with unique trace. Furthermore for any fixed countable subgroup GG of R+×\mathbb{R}_+^{\times}, there exist uncountably many mutually nonisomorphic such algebras AA with G=F(A)G = \mathcal{F}(A).

Keywords

Cite

@article{arxiv.0911.0238,
  title  = {Fundamental group of simple $C^*$-algebras with unique trace II},
  author = {Norio Nawata and Yasuo Watatani},
  journal= {arXiv preprint arXiv:0911.0238},
  year   = {2010}
}

Comments

8 pages, added some results