English

Finite-dimensional approximation properties for uniform Roe algebras

Operator Algebras 2020-04-15 v4 Group Theory Metric Geometry

Abstract

We study property A for metric spaces XX with bounded geometry introduced by Guoliang Yu. Property A is an amenability-type condition, which is less restrictive than amenability for groups. The property has a connection with finite-dimensional approximation properties in the theory of operator algebras. It has been already known that property A of a metric space XX with bounded geometry is equivalent to nuclearity of the uniform Roe algebra Cu(X)^*_u(X). We prove that exactness and local reflexivity of Cu(X)^*_u(X) also characterize property A of XX.

Keywords

Cite

@article{arxiv.1212.5900,
  title  = {Finite-dimensional approximation properties for uniform Roe algebras},
  author = {Hiroki Sako},
  journal= {arXiv preprint arXiv:1212.5900},
  year   = {2020}
}

Comments

22 pages, simpler proof than v1, title changed, to appear in JLMS

R2 v1 2026-06-21T22:59:45.384Z