Approximation Properties for Crossed Products by Actions and Coactions

2001/07/10 by May Nilsen, Roger Smith, Nilsen, May +1
Mathematics · #46L10 #FOS: Mathematics #Operator Algebras (math.OA) #math.OA #msc:46L10

paper · pdf · doi:10.48550/arxiv.math/0107074

17 pages, latex file, Internat. J. Math. to appear

arxiv created 2001/07/10 · arxiv updated 2009/11/30

Abstract

We investigate approximation properties for C^*-algebras and their crossed products by actions and coactions by locally compact groups. We show that Haagerup's approximation constant is preserved for crossed products by arbitrary amenable groups, and we show why this is not always true in the non-amenable case. We also examine similar questions for other forms of the approximation property.

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