English
Related papers

Related papers: On Exel-Pardo algebras

200 papers

A $\lambda$-graph system is a labeled Bratteli diagram with certain additional structure, which presents a subshift. The class of the $C^*$-algebras $\mathcal{O}_{\frak L}$ associated with the $\lambda$-graph systems is a generalized class…

Operator Algebras · Mathematics 2024-05-29 Kengo Matsumoto

We show that the $C^*$-algebra of a countable directed graph is singly generated. As a consequence, any $C^*$-algebra generated by a countable family of projections and partial isometries satisfying Cuntz-Krieger relations is singly…

Operator Algebras · Mathematics 2026-01-06 Jakub Curda , Julian Gonzales , Victor Wu

In this paper we study Cuntz--Pimsner algebras associated to $\mathrm{C}^*$-correspondences over commutative $\mathrm{C}^*$-algebras from the point of view of the $\mathrm{C}^*$-algebra classification programme. We show that when the…

Let $E$ be a finite directed graph with no sources or sinks and write $X_E$ for the graph correspondence. We study the $C^*$-algebra $C^*(E,Z):=\mathcal{T}(X_E,Z)/\mathcal{K}$ where $\mathcal{T}(X_E,Z)$ is the $C^*$-algebra generated by…

Operator Algebras · Mathematics 2021-08-13 Leonid Helmer , Baruch Solel

Let $G=K\ltimes A$ be the semi-direct product group of a compact group $K$ acting on an abelian locally compact group $A$. We describe the $C^*$-algebra $C^*(G)$ of $G$ in terms of an algebra of operator fields defined over the spectrum of…

Operator Algebras · Mathematics 2019-04-23 Hedi Regeiba , Jean Ludwig

Let $P$ be a unital subsemigroup of a group $G$. We propose an approach to $\mathrm{C}^*$-algebras associated to product systems over $P$. We call the $\mathrm{C}^*$-algebra of a given product system $\mathcal{E}$ its covariance algebra and…

Operator Algebras · Mathematics 2018-11-21 Camila F. Sehnem

We study strong compactly aligned product systems of $\mathbb{Z}_+^N$ over a C*-algebra $A$. We provide a description of their Cuntz-Nica-Pimsner algebra in terms of tractable relations coming from ideals of $A$. This approach encompasses…

Operator Algebras · Mathematics 2019-07-17 Adam Dor-On , Evgenios T. A. Kakariadis

We consider directed graphs E which have been obtained by adding a sink to a fixed graph G. We associate an element of Ext(C*(G)) to each such E, and show that the classes of two such graphs are equal in Ext(C*(G)) if and only if the…

Operator Algebras · Mathematics 2007-05-23 Mark Tomforde

The structure of the $C^*$-algebras corresponding to even-dimensional mirror quantum spheres is investigated. It is shown that they are isomorphic to both Cuntz-Pimsner algebras of certain $C^*$-correspondences and $C^*$-algebras of certain…

Operator Algebras · Mathematics 2010-12-15 David Robertson , Wojciech Szymański

We consider a family of dynamical systems (A,alpha,L) in which alpha is an endomorphism of a C*-algebra A and L is a transfer operator for \alpha. We extend Exel's construction of a crossed product to cover non-unital algebras A, and show…

Operator Algebras · Mathematics 2015-05-13 Nathan Brownlowe , Iain Raeburn , Sean T. Vittadello

In this paper we describe a new method of defining C*-algebras from oriented combinatorial data, thereby generalizing the constructions of algebras from directed graphs, higher-rank graphs, and ordered groups. We show that only the most…

Operator Algebras · Mathematics 2014-05-21 Jack Spielberg

We define partial product systems over N. They generalise product systems over N and Fell bundles over Z. We define Toeplitz C*-algebras and relative Cuntz-Pimsner algebras for them and show that the section C*-algebra of a Fell bundle over…

Operator Algebras · Mathematics 2019-12-23 Devarshi Mukherjee , Ralf Meyer

These notes were originally intended to be complementary material for an introductory course on self-similar graphs and their algebras, presented by the author at the CIMPA School ``K-theory and Operator Algebras'', held in La Plata and…

Operator Algebras · Mathematics 2025-09-24 Enrique Pardo

In this paper we extend the constructions of Boava and Exel to present the C*-algebra associated with an injective endomorphism of a group with finite cokernel as a partial group algebra and consequently as a partial crossed product. With…

Operator Algebras · Mathematics 2017-07-12 Felipe Vieira

We study the ideal structure of $C^*$-algebras arising from $C^*$-correspondences. We prove that gauge-invariant ideals of our $C^*$-algebras are parameterized by certain pairs of ideals of original $C^*$-algebras. We show that our…

Operator Algebras · Mathematics 2007-05-23 Takeshi Katsura

In this paper, we introduce the notion of a dual topological graph of a given topological graph, and show that it defines a C*-algebra isomorphic to the C*-algebra of the given one. Repeating to take a dual, and taking a projective limit,…

Operator Algebras · Mathematics 2021-07-06 Takeshi Katsura

Certain $*$-semigroups are associated with the universal $C^*$-algebra generated by a partial isometry, which is itself the universal $C^*$-algebra of a $*$-semigroup. A fundamental role for a $*$-structure on a semigroup is emphasized, and…

Operator Algebras · Mathematics 2014-06-03 Berndt Brenken

Building on recent work of Robertson and Steger, we associate a C*-algebra to a combinatorial object which may be thought of as a higher rank graph. This C*-algebra is shown to be isomorphic to that of the associated path groupoid.…

Operator Algebras · Mathematics 2007-05-23 Alex Kumjian , David Pask

Motivated by Exel's inverse semigroup approach to combinatorial C*-algebras, in a previous work the authors defined an inverse semigroup associated with a labelled space. We construct a representation of the C*-algebra of a labelled space,…

Operator Algebras · Mathematics 2019-09-11 Giuliano Boava , Gilles G. de Castro , Fernando de L. Mortari

We classify graph C*-algebras, namely, Cuntz-Krieger algebras associated to the Bass-Hashimoto edge incidence operator of a finite graph. This is done by a purely graph theoretical calculation of the K-theory and the position of the unit…

Operator Algebras · Mathematics 2007-05-23 Gunther Cornelissen , Oliver Lorscheid , Matilde Marcolli
‹ Prev 1 4 5 6 7 8 10 Next ›