Subalgebras of simple AF-algebras

2018/07/19 by Schafhauser, Christopher · 2 citations
#FOS: Mathematics #Operator Algebras (math.OA)

paper · doi:10.48550/arxiv.1807.07381

Abstract

It is shown that if A is a separable, exact C*-algebra which satisfies the Universal Coefficient Theorem (UCT) and has a faithful, amenable trace, then A admits a trace-preserving embedding into a simple, unital AF-algebra with unique trace. Modulo the UCT, this provides an abstract characterization of C*-subalgebras of simple, unital AF-algebras. As a consequence, for a countable, discrete, amenable group G acting on a second countable, locally compact, Hausdorff space X, C₀(X) \rtimes_r G embeds into a simple, unital AF-algebra if, and only if, X admits a faithful, invariant, Borel, probability measure. Also, for any countable, discrete, amenable group G, the reduced group C*-algebra C*_r(G) admits a trace-preserving embedding into the universal UHF-algebra.

Cited by

• Centrally pure C*-algebras
• Selfless reduced free products and graph products of C^∗-algebras

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