Rokhlin dimension for actions of residually compact groups

Xin Cao; Xiaochun Fang; Jianchao Wu

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arXiv · 2601.15694

Rokhlin dimension for actions of residually compact groups

Xin Cao·Xiaochun Fang·Jianchao Wu

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Abstract

We introduce the concept of Rokhlin dimension for actions of residually compact groups on C*-algebras, which extends and unifies previous notions for actions of compact groups, residually finite groups and the reals. We then demonstrate that finite nuclear dimension (respectively, absorption of a strongly self-absorbing C*-algebra) is preserved under the formation of crossed products by residually compact group actions with finite Rokhlin dimension (respectively, finite Rokhlin dimension with commuting towers). Furthermore, if second countable residually compact group contains a non-open cocompact closed subgroup, then crossed products arising from actions with finite Rokhlin dimension are stable. Finally, we study the relationship between the tube dimension of a topological dynamical system and the Rokhlin dimension of the induced C*-dynamical system.

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Xin Cao, Xiaochun Fang, Jianchao Wu. 2026-02-02. Rokhlin dimension for actions of residually compact groups. https://arxiv.org/abs/2601.15694

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