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Related papers: The Crossed Product by a Partial Endomorphism

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We start from Rieffel data (A,f,X) where A is a C*-algebra, X is an action of an abelian group H on A and f is a 2-cocycle on the dual group. Using Landstad theory of crossed product we get a deformed C*-algebra A(f). In the case of H being…

Operator Algebras · Mathematics 2010-07-30 P. Kasprzak

The dynamics of a one-sided subshift $\mathsf{X}$ can be modeled by a set of partially defined bijections. From this data we define an inverse semigroup $\mathcal{S}_{\mathsf{X}}$ and show that it has many interesting properties. We prove…

Operator Algebras · Mathematics 2022-08-18 Charles Starling

von Neumann algebras have been playing an increasingly important role in the context of gauge theories and gravity. The crossed product presents a natural method for implementing constraints through the commutation theorem, rendering it a…

High Energy Physics - Theory · Physics 2025-02-10 Shadi Ali Ahmad , Marc S. Klinger , Simon Lin

Let (G,P) be a quasi-lattice ordered group and let X be a compactly aligned product system over P of Hilbert bimodules. Under mild hypotheses we associate to X a C*-algebra which we call the Cuntz-Nica-Pimsner algebra of X. Our construction…

Operator Algebras · Mathematics 2009-01-08 Aidan Sims , Trent Yeend

Let $\A$ be a unital operator algebra and let $\alpha$ be an automorphism of $\A$ that extends to a *-automorphism of its $\ca$-envelope $\cenv (\A)$. In this paper we introduce the isometric semicrossed product $\A \times_{\alpha}^{\is}…

Operator Algebras · Mathematics 2014-04-08 Evgenios Kakariadis , Elias Katsoulis

A C*-dynamical system is said to have the ideal separation property if every ideal in the corresponding crossed product arises from an invariant ideal in the C*-algebra. In this paper we characterize this property for unital C*-dynamical…

Operator Algebras · Mathematics 2019-12-19 Matthew Kennedy , Christopher Schafhauser

In this note we show that a combinatorial model of Kirchberg algebras in the UCT, namely the Katsura algebras O_{AB}, can be expressed both as groupoid C*-algebras and as inverse semigroup crossed products. We use this picture to obtain…

Operator Algebras · Mathematics 2013-04-24 Ruy Exel , Enrique Pardo

Let $V$ be an operator space and $\iso(V)$ be the group of all completely isometric bijective linear mappings on $V$. Let $G$ act on $V$ via a strongly continuous group homomorphism $\alpha:G \to \iso (V)$. We define the full (and reduced)…

Operator Algebras · Mathematics 2016-02-16 Massoud Amini , Siegfried Echterhoff , Hamed Nikpey

We show that if $(X.A)$ and $(Y,B)$ are two isomorphic Hilbert pro-$C^{\ast} $-bimodules, then the crossed product $A\times_{X}\mathbb{Z}$ of $A$ by $X$ and the crossed product $B\times_{Y}\mathbb{Z}$ of $B$ by $Y$ are isomorphic as…

Operator Algebras · Mathematics 2015-02-17 Maria Joiţa

All physical observations are made relative to a reference frame, which is a system in its own right. If the system of interest admits a group symmetry, the reference frame observing it must transform commensurately under the group to…

High Energy Physics - Theory · Physics 2024-07-03 Shadi Ali Ahmad , Wissam Chemissany , Marc S. Klinger , Robert G. Leigh

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

If $\alpha$ is the endomorphism of the disk algebra, $\AD$, induced by composition with a finite Blaschke product $b$, then the semicrossed product $\AD\times_{\alpha} \bZ^+$ imbeds canonically, completely isometrically into…

Operator Algebras · Mathematics 2011-04-08 Kenneth R. Davidson , Elias G. Katsoulis

The relations between the radical of crossed product $R #_\sigma H$ and algebra $R$ are obtained. Using this theory, the author shows that if $H$ is a finite-dimensional semisimple, cosemisimle, and either commutative or cocommutative Hopf…

Quantum Algebra · Mathematics 2007-05-23 Shouchuan Zhang

We investigate $C^*$-algebras associated with row-finite topological higher-rank graphs with no source, which are based on product system $C^*$-algebras. We prove the Cuntz-Krieger uniqueness theorem, and provide the condition of simplicity…

Operator Algebras · Mathematics 2009-06-18 Shinji Yamashita

We propose a generalisation of Exel's crossed product by a single endomorphism and a transfer operator to the case of actions of abelian semigroups of endomorphisms and associated transfer operators. The motivating example for our…

Operator Algebras · Mathematics 2007-05-23 Nadia S. Larsen

We study simplicity and pure infiniteness criteria for C*-algebras associated to inverse semigroup actions by Hilbert bimodules and to Fell bundles over etale not necessarily Hausdorff groupoids. Inspired by recent work of Exel and Pitts,…

Operator Algebras · Mathematics 2021-08-17 B. K. Kwasniewski , R. Meyer

Given a Hausdorff compact space X, we study the C^*-(semi)-norms on the algebraic tensor product $A\otimes_{alg,C(X)} B$ of two C(X)-algebras A and B over C(X). In particular, if one of the two C(X)-algebras defines a continuous field of…

Operator Algebras · Mathematics 2016-09-07 Etienne Blanchard

We consider a family of Hecke C*-algebras which can be realised as crossed products by semigroups of endomorphisms. We show by dilating representations of the semigroup crossed product that the category of representations of the Hecke…

Operator Algebras · Mathematics 2007-05-23 Nadia S. Larsen , Iain Raeburn

We consider group actions of topological groups on C*-algebras of the types which occur in many physics models. These are singular actions in the sense that they need not be strongly continuous, or the group need not be locally compact. We…

Operator Algebras · Mathematics 2012-10-16 Hendrik Grundling , Karl-Hermann Neeb

We prove a result concerning the inclusion of non-trivial invariant ideals inside non-trivial ideals of a twisted crossed product. We will also give results concerning the primeness and simplicity of crossed products of twisted actions of…

Operator Algebras · Mathematics 2007-05-23 Chi-Wai Leung , Chi-Keung Ng