Rokhlin dimension for actions of residually finite groups

Abstract

We introduce the concept of Rokhlin dimension for actions of residually finite groups on C*-algebras, extending previous notions of Rokhlin dimension for actions of finite groups and the integers, as introduced by Hirshberg, Winter and the third author. If the group has a box space of finite asymptotic dimension, then actions with finite Rokhlin dimension preserve the property of having finite nuclear dimension, when passing to the crossed product C*-algebra. A detailed study of the asymptotic dimension of box spaces shows that finitely generated, virtually nilpotent groups have box spaces with finite asymptotic dimension, providing a reasonably large class of examples. We then establish a relation between Rokhlin dimension of residually finite groups acting on compact metric spaces and amenability dimension of the action in the sense of Guentner, Willett and Yu. We show that for free actions of infinite, finitely generated, nilpotent groups on finite dimensional spaces, both these dimensional values are finite. In particular, the associated transformation group C*-algebras have finite nuclear dimension. This extends an analogous result about ${\mathbb{Z}}^m$-actions by the first author. We also provide some results concerning the genericity of finite Rokhlin dimension, and permanence properties with respect to the absorption of a strongly self-absorbing C*-algebra.

64 pages; some small corrections and added remarks

References in corpus (12)

• Quasidiagonality of nuclear C*-algebras
• Completely positive maps of order zero
• Nuclear dimension and Z-stability
• Strongly self-absorbing C*-dynamical systems
• Strongly self-absorbing C*-dynamical systems, III
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• Coarse flow spaces for relatively hyperbolic groups
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Cited by in corpus (10)

• Strongly self-absorbing C*-dynamical systems, II
• The Rokhlin property vs. Rokhlin dimension 1 on unital Kirchberg algebras
• The nuclear dimension of C*-algebras associated to homeomorphisms
• Dynamic Asymptotic Dimension: relation to dynamics, topology, coarse geometry, and $C^{\ast }$-algebras
• Sofic boundaries of groups and coarse geometry of sofic approximations
• Groupoid Models of $C^{\ast }$-algebras and Gelfand Duality
• Cartan subalgebras in C*-algebras. Existence and uniqueness
• On equivariant asymptotic dimension
• Equi-variant and Stable Finite Decomposition Complexity
• Partial C*-dynamics and Rokhlin dimension