English

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

K-Theory and Homology 2016-01-20 v3 Group Theory Metric Geometry Operator Algebras Representation Theory

Abstract

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.

Keywords

Cite

@article{arxiv.1311.2343,
  title  = {Expanders, exact crossed products, and the Baum-Connes conjecture},
  author = {Paul Baum and Erik Guentner and Rufus Willett},
  journal= {arXiv preprint arXiv:1311.2343},
  year   = {2016}
}

Comments

53 pages. Some (relatively minor) changes and corrections

R2 v1 2026-06-22T02:04:41.782Z