English

Deformations of Wreath Products

Operator Algebras 2023-11-27 v1 K-Theory and Homology

Abstract

Connectivity is a homotopy invariant property of a separable C*-algebra A which has three important consequences: absence of nontrivial projections, quasidiagonality and realization of the Kasparov group KK(A,B) as homotopy classes of asymptotic morphisms from A to the stabilization of B if A is nuclear. Here we give a new characterization of connectivity for separable exact C*-algebras and use this characterization to show that the class of discrete countable amenable groups whose augmentation ideals are connective is closed under generalized wreath products. In a related circle of ideas, we give a result on quasidiagonality of reduced crossed-product C*-algebras associated to noncommutative Bernoulli actions.

Keywords

Cite

@article{arxiv.1609.00604,
  title  = {Deformations of Wreath Products},
  author = {Marius Dadarlat and Ulrich Pennig and Andrew Schneider},
  journal= {arXiv preprint arXiv:1609.00604},
  year   = {2023}
}