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

2009/11/02 by Norio Nawata, Nawata, Norio, Yasuo Watatani +1
Mathematics · #46L08 #46L35 #FOS: Mathematics #Functional Analysis (math.FA) #Operator Algebras (math.OA) #math.FA #math.OA #msc:46L08 #msc:46L35

paper · pdf · doi:10.48550/arxiv.0911.0238

8 pages, added some results

arxiv created 2010/06/22 · arxiv updated 2010/06/23

Abstract

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

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