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Related papers: Group actions on Smale space C*-algebras

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In this paper, we study boundary actions of CAT(0) spaces from a point of view of topological dynamics and $C^*$-algebras. First, we investigate the actions of right-angled Coexter groups and right-angled Artin groups with finite defining…

Operator Algebras · Mathematics 2022-03-01 Xin Ma , Daxun Wang

When S is a discrete subsemigroup of a discrete group G such that G = S^{-1} S, it is possible to extend circle-valued multipliers from S to G; to dilate (projective) isometric representations of S to (projective) unitary representations of…

Operator Algebras · Mathematics 2007-05-23 Marcelo Laca

We study partial actions of exact discrete groups on C*-algebras. We show that the partial crossed product of a commutative C*-algebra by an exact discrete group is nuclear whenever the full and reduced partial crossed products coincide.…

Operator Algebras · Mathematics 2022-02-14 Alcides Buss , Damián Ferraro , Camila F. Sehnem

We introduce algebraic dynamical systems, which consist of an action of a right LCM semigroup by injective endomorphisms of a group. To each algebraic dynamical system we associate a C*-algebra and describe it as a semigroup C*-algebra. As…

Operator Algebras · Mathematics 2019-02-08 Nathan Brownlowe , Nadia S. Larsen , Nicolai Stammeier

Let $A$ be a simple separable nuclear C$^*$-algebra with a unique tracial state and no unbounded traces, and let $\alpha$ be a strongly outer action of a finite group $G$ on $A$. In this paper, we show that $\alpha\otimes \mathrm{id}$ on…

Operator Algebras · Mathematics 2019-10-04 Norio Nawata

We introduce dynamic asymptotic dimension, a notion of dimension for actions of discrete groups on locally compact spaces, and more generally for locally compact \'etale groupoids. We study our notion for minimal actions of the integer…

Dynamical Systems · Mathematics 2015-10-28 Erik Guentner , Rufus Willett , Guoliang Yu

We study actions of discrete groups on Hilbert $C^*$-modules induced from topological actions on compact Hausdorff spaces. We show non-amenability of actions of non-amenable and non-a-T-menable groups, provided there exists a…

Functional Analysis · Mathematics 2011-08-09 Ronald G. Douglas , Piotr W. Nowak

We define spectral freeness for actions of discrete groups on C*-algebras. We relate spectral freeness to other freeness conditions; an example result is that for an action of a finite group, spectral freeness is equivalent to strong…

Operator Algebras · Mathematics 2013-08-23 Cornel Pasnicu , N. Christopher Phillips

Let $P \subset A$ be an inclusion of $\sigma$-unital C*-algebras with a finite index in the sense of Izumi. Then we introduce the Rokhlin property for a conditional expectation $E$ from $A$ onto $P$ and show that if $A$ is simple and…

Operator Algebras · Mathematics 2018-03-23 Hiroyuki Osaka , Tamotsu Teruya

We prove that for any second-countable, locally compact group $G$, any continuous $G$-action on the primitive ideal space of a separable, nuclear $\mathrm{C}^{\ast}$-algebra $B$ such that $B \cong B\otimes\mathcal{K}\otimes\mathcal{O}_2$ is…

Operator Algebras · Mathematics 2024-11-12 Matteo Pagliero

Let $V$ be an irreducible complex analytic space of dimension two with normal singularities and $\vr:\mathbb{C^*}\times V\to V$ a holomorphic action of the group $\mathbb{C^*}$ on $V$. Denote by $\fa_\vr$ the foliation on $V$ induced by…

Complex Variables · Mathematics 2007-09-06 Cesar Camacho , Hossein Movasati , Bruno Scardua

We extend Nekrashevych's $KK$-duality for $C^*$-algebras of regular, recurrent, contracting self-similar group actions to regular, contracting self-similar groupoid actions on a graph, removing the recurrence condition entirely and…

K-Theory and Homology · Mathematics 2023-12-05 Nathan Brownlowe , Alcides Buss , Daniel Gonçalves , Jeremy B. Hume , Aidan Sims , Michael F. Whittaker

We give the first examples of (non-amenable group) amenable actions on stably finite simple C*-algebras. More precisely, we give such actions for any countable group in an explicit way. The main ingredients of our construction are the full…

Operator Algebras · Mathematics 2026-02-09 Yuhei Suzuki

Finite rank median spaces are a simultaneous generalisation of finite dimensional ${\rm CAT}(0)$ cube complexes and real trees. If $\Gamma$ is an irreducible lattice in a product of rank one simple Lie groups, we show that every action of…

Geometric Topology · Mathematics 2019-07-02 Elia Fioravanti

Cohomogeneity one actions on irreducible Riemannian symmetric spaces of compact type are classified into three cases: Hermann actions, actions induced by the linear isotropy representation of a Riemannian symmetric space of rank 2, and…

Differential Geometry · Mathematics 2025-04-17 Shinji Ohno , Yuuki Sasaki

We investigate symmetries on unital Kirchberg algebras with respect to the Rokhlin property and finite Rokhlin dimension. In stark contrast to the restrictiveness of the Rokhlin property, every such outer action has Rokhlin dimension at…

Operator Algebras · Mathematics 2016-10-27 Selcuk Barlak , Dominic Enders , Hiroku Matui , Gabor Szabo , Wilhelm Winter

We define the local multiplier module of a Hilbert module in analogy to the local multiplier algebra for $C^*$-algebras. We use properties of the local multiplier module to lift non-closed actions on $C^*$-algebras by Hilbert bimodules to…

Operator Algebras · Mathematics 2023-03-21 Jonathan Taylor

This paper is a further study of finite Rokhlin dimension for actions of finite groups and the integers on C*-algebras, introduced by the first author, Winter, and Zacharias. We extend the definition of finite Rokhlin dimension to the…

Operator Algebras · Mathematics 2015-02-23 Ilan Hirshberg , N. Christopher Phillips

We prove that, given any smooth action of a compact quantum group (in the sense of \cite{rigidity}) on a compact smooth manifold satisfying some more natural conditions, one can get a Riemannian structure on the manifold for which the…

Operator Algebras · Mathematics 2015-03-19 Debashish Goswami , Soumalya Joardar

We study the topological dynamics of the action of an acylindrically hyperbolic group on the space of its infinite index convex cocompact subgroups by conjugation. We show that, for any suitable probability measure $\mu$, random walks with…

Group Theory · Mathematics 2025-01-10 M. Hull , A. Minasyan , D. Osin