Expanders, exact crossed products, and the Baum-Connes conjecture

Paul Baum, Erik Guentner, Rufus Willett

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


We reformulate the Baum-Connes conjecture with coefficients by introducing a new crossed product functor for C*-algebras. All confirming examples for the original Baum-Connes conjecture remain confirming examples for the reformulated conjecture, and at present there are no known counterexamples to the reformulated conjecture. Moreover, some of the known expander-based counterexamples to the original Baum-Connes conjecture become confirming examples for our reformulated conjecture.

Original languageEnglish (US)
Pages (from-to)155-208
Number of pages54
JournalAnnals of K-Theory
Issue number2
StatePublished - 2016

All Science Journal Classification (ASJC) codes

  • Analysis
  • Geometry and Topology


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