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

摘要

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).