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Related papers: Crossed products of operator systems

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Starting from a discrete $C^*$-dynamical system $(\mathfrak{A}, \theta, \omega_o)$, we define and study most of the main ergodic properties of the crossed product $C^*$-dynamical system $(\mathfrak{A}\rtimes_\alpha\mathbb{Z}, \Phi_{\theta,…

Operator Algebras · Mathematics 2021-05-04 Simone Del Vecchio , Francesco Fidaleo , Stefano Rossi

Given a weak Kac system with duality $(\mathcal{H},V,U)$ arising from regular $\mathrm{C}^{*}$-algebraic locally compact quantum group $(\mathcal{G},\Delta)$, a $\mathrm{C}^{*}$-algebra $A$, and a sufficiently well-behaved coaction…

Operator Algebras · Mathematics 2025-04-17 Matthew Gillespie

In this work we present a new definition to the Partial Crossed Product by actions of inverse semigroups in a C^*-algebra, without using the covariant representations as Sieben did in [5]. Also we present an isomorphism between the partial…

Operator Algebras · Mathematics 2008-05-26 Ruy Exel , Felipe Vieira

We have introduced a notion of $C^*$-symbolic dynamical system in [K. Matsumoto: Actions of symbolic dynamical systems on $C^*$-algebras, to appear in J. Reine Angew. Math.], that is a finite family of endomorphisms of a $C^*$-algebra with…

Operator Algebras · Mathematics 2007-05-24 Kengo Matsumoto

We consider a free action of an Ore semigroup on a higher-rank graph, and the induced action by endomorphisms of the $C^*$-algebra of the graph. We show that the crossed product by this action is stably isomorphic to the $C^*$-algebra of a…

Operator Algebras · Mathematics 2013-05-17 Ben Maloney , David Pask , Iain Raeburn

Semicrossed product algebras have been used to study dynamical systems since their introduction by Arveson in 1967. In this survey article, we discuss the history and some recent work, focussing on the conjugacy problem, dilation theory and…

Operator Algebras · Mathematics 2020-01-24 Kenneth R. Davidson , Adam H. Fuller , Evgenios T. A. Kakariadis

We study actions of countable discrete amenable groups on unital separable simple nuclear Z-absorbing C*-algebras. Under a certain assumption on tracial states, which is automatically satisfied in the case of a unique tracial state, the…

Operator Algebras · Mathematics 2016-12-28 Yasuhiko Sato

We construct a crossed product Banach algebra from a Banach algebra dynamical system $(A,G,\alpha)$ and a given uniformly bounded class $R$ of continuous covariant Banach space representations of that system. If $A$ has a bounded left…

Functional Analysis · Mathematics 2011-08-16 Sjoerd Dirksen , Marcel de Jeu , Marten Wortel

We characterise stable finiteness and pure infiniteness of the essential crossed product of a C*-algebra by an action of an inverse semigroup. Under additional assumptions, we prove a stably finite / purely infinite dichotomy. Our main…

Operator Algebras · Mathematics 2026-01-13 Becky Armstrong , Lisa Orloff Clark , Astrid An Huef , Diego Martínez , Ilija Tolich

We establish comparison and divisibility properties for crossed product C*-algebras arising from automorphisms of algebras C (X, D) which lie over minimal homeomorphisms, from actions of compact groups which have finite Rokhlin dimension…

Operator Algebras · Mathematics 2026-04-14 Dawn Archey , Julian Buck , Javad Mohammadkarimi , N. Christopher Phillips , Apurva Seth

In this paper we analyse for a $G$-$C^{*}$-algebra $A$ to which extent one can calculate the $K$-theory of the reduced crossed product $K(A\rtimes_{r}G)$ from the $K$-theory spectrum $K(A)$ with the induced $G$-action. We also consider some…

Operator Algebras · Mathematics 2023-11-29 Ulrich Bunke

The notions of Busby-Smith and Green type twisted actions are extended to discrete unital inverse semigroups. The connection between the two types, and the connection with twisted partial actions, are investigated. Decomposition theorems…

funct-an · Mathematics 2007-05-23 Nandor Sieben

We survey the extensions of a group by a group using crossed products instead of exact sequences of groups. The approach has various advantages, one of them being that the crossed product is an universal object. Several new applications are…

Group Theory · Mathematics 2014-03-18 A. L. Agore , G. Militaru

We consider a certain class of unital simple stably finite C^*-algebras which absorb the Jiang-Su algebra Z tensorially. Under a mild assumption, we show that the crossed product of a C^*-algebra in this class by a strongly outer action of…

Operator Algebras · Mathematics 2011-07-05 Hiroki Matui , Yasuhiko Sato

If $\alpha$ is an amenable action of a discrete group $G$ on a unital C*-algebra $A$, then the crossed-product C*-algebra $A\rtimes_\alpha G$ has the weak expectation property if and only if $A$ has this property.

Operator Algebras · Mathematics 2013-07-26 Angshuman Bhattacharya , Douglas Farenick

We study the relationship between the ultraproduct of a crossed product C*algebra $(A\rtimes_{r}G)^{\omega}$ and the crossed product of an ultraproduct C*algebra $A^{\omega}\rtimes _{r}G$ for a fixed free ultrafilter $\omega$ on…

Operator Algebras · Mathematics 2026-02-24 Zhengyu Fu

Families of codes such as group codes, constacyclic and skew cyclic codes, some of which independently suggested in the literature, turn out to be special instances of the general family of crossed product codes. Hamming-metric is a main…

Rings and Algebras · Mathematics 2018-11-06 Yuval Ginosar , Aviram Rochas Moreno

Laca constructed a minimal automorphic dilation for every semigroup dynamical system arising from an action of an Ore semigroup by injective endomorphisms of a unital $C^*$-algebra. Here we show that the semigroup crossed product with its…

Operator Algebras · Mathematics 2010-09-30 Nadia S. Larsen , Xin Li

We provide a reference for basic categorial properties of the categories of (possibly non-unital) $\mathbb{C}$-linear $*$-categories or $C^{*}$-categories, and (not necessarily unit-preserving) functors. Generalizing the classical case of…

Operator Algebras · Mathematics 2021-12-13 Ulrich Bunke

To a continuous action of a vector group on a $C^*$-algebra, twisted by the imaginary exponential of a symplectic form, one associates a Rieffel deformed algebra as well as a twisted crossed product. We show that the second one is…

Operator Algebras · Mathematics 2014-06-30 I. Beltita , M. Mantoiu