2009/07/13 by Ján Špakula, Spakula, Jan
Mathematics · #46L80 #Advanced Operator Algebra Research #Advanced Topics in Algebra #Algebraic structures and combinatorial models #FOS: Mathematics #Operator Algebras (math.OA)
paper · pdf · doi:10.48550/arxiv.0907.2249
openalex publication_date 2009/07/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We prove that uniform Roe C*-algebras associated to some expander graphs coming from discrete groups with property (τ) are not K-exact. In particular, we show that this is the case for the expander obtained as Cayley graphs of a sequence of alternating groups (with appropriately chosen generating sets).