English
Related papers

Related papers: Moves on $k$-graphs preserving Morita equivalence

200 papers

As recently pointed out by Gabe, a fundamental paper by Elliott and Kucerovsky concerning the absorption theory for C*-algebras contains an error, and as a consequence we must report that Lemma 4.5 in "Classifying C*-algebras with both…

Operator Algebras · Mathematics 2021-09-20 Søren Eilers , Gunnar Restorff , Efren Ruiz

We define the categorical cohomology of a k-graph \Lambda\ and show that the first three terms in this cohomology are isomorphic to the corresponding terms in the cohomology defined in our previous paper. This leads to an alternative…

Operator Algebras · Mathematics 2013-08-15 Alex Kumjian , David Pask , Aidan Sims

We show that every subset of vertices of a directed graph E gives a Morita equivalence between a subalgebra and an ideal of the associated Leavitt path algebra. We use this observation to prove an algebraic version of a theorem of Crisp and…

Rings and Algebras · Mathematics 2017-01-13 Lisa Orloff Clark , Astrid an Huef , Pareoranga Luiten-Apirana

We analyze in the context of Leavitt path algebras some graph operations introduced in the context of symbolic dynamics by Williams, Parry and Sullivan, and Franks. We show that these operations induce Morita equivalence of the…

Rings and Algebras · Mathematics 2011-01-20 G. Abrams , A. Louly , E. Pardo , C. Smith

We describe a class of $C^*$-algebras which simultaneously generalise the ultragraph algebras of Tomforde and the shift space $C^*$-algebras of Matsumoto. In doing so we shed some new light on the different $C^*$-algebras that may be…

Operator Algebras · Mathematics 2007-05-23 Teresa Bates , David Pask

We consider two twisted actions of a countable discrete group on $\sigma$-unital $C^*$-algebras. Then by taking the reduced crossed products, we get two inclusions of $C^*$-algebras. We suppose that they are strongly Morita equivalent as…

Operator Algebras · Mathematics 2020-11-16 Kazunori Kodaka

The goal of these notes is to present the C*-algebra $C^*(B,L,\theta)$ of a Boolean dynamical system $(B,L,\theta)$, that generalizes the $C^*$-algebra associated to Labelled graphs introduced by Bates and Pask, and to determine its…

Operator Algebras · Mathematics 2017-05-23 Toke Meier Carlsen , Eduard Ortega , Enrique Pardo

This dissertation concerns the classification of groupoid and higher-rank graph C*-algebras and has two main components. Firstly, for a groupoid it is shown that the notions of strength of convergence in the orbit space and…

Operator Algebras · Mathematics 2013-05-28 Robert Hazlewood

Many interesting examples of operator algebras, both self-adjoint and non-self-adjoint, can be constructed from directed graphs. In this survey, we overview the construction of $C^*$-algebras from directed graphs and from two…

Operator Algebras · Mathematics 2022-09-07 Juliana Bukoski , Sushil Singla

Higher-rank graphs (or $k$-graphs) were introduced by Kumjian and Pask to provide combinatorial models for the higher-rank Cuntz-Krieger $C^*$-algebras of Robertson and Steger. Here we consider a family of finite 2-graphs whose path spaces…

Operator Algebras · Mathematics 2008-04-23 David Pask , Iain Raeburn , Natasha A. Weaver

We define $A_k$-moves for embeddings of a finite graph into the 3-sphere for each natural number $k$. Let $A_k$-equivalence denote an equivalence relation generated by $A_k$-moves and ambient isotopy. $A_k$-equivalence implies…

Geometric Topology · Mathematics 2007-05-23 Kouki Taniyama , Akira Yasuhara

We show that the C*-algebra of a row-finite source-free k-graph is Rieffel-Morita equivalent to a crossed product of an AF algebra by the fundamental group of the k-graph. When the k-graph embeds in its fundamental groupoid, this AF algebra…

Operator Algebras · Mathematics 2024-03-05 Nathan Brownlowe , Alex Kumjian , David Pask , Aidan Sims

We consider two categories of C*-algebras; in the first, the isomorphisms are ordinary isomorphisms, and in the second, the isomorphisms are Morita equivalences. We show how these two categories, and categories of dynamical systems based on…

Operator Algebras · Mathematics 2009-09-16 Astrid an Huef , Iain Raeburn , Dana Williams

Let G be a (not necessarily Hausdorff) locally compact groupoid. We introduce a notion of properness for G, which is invariant under Morita-equivalence. We show that any generalized morphism between two locally compact groupoids which…

Operator Algebras · Mathematics 2007-05-23 Jean-Louis Tu

The representations of a $k$-graph $C^*$-algebra $C^*(\Lambda)$ which arise from $\Lambda$-semibranching function systems are closely linked to the dynamics of the $k$-graph $\Lambda$. In this paper, we undertake a systematic analysis of…

Operator Algebras · Mathematics 2021-02-09 Carla Farsi , Elizabeth Gillaspy , Daniel Gonçalves

We investigate the use of labelled graphs as a Morita equivalence invariant for inverse semigroups. We construct a labelled graph from a combinatorial inverse semigroup $S$ with $0$ admitting a special set of idempotent $\mathcal{D}$-class…

Group Theory · Mathematics 2025-03-17 Zachary Duah , Stian Du Preez , David Milan , Shreyas Ramamurthy , Lucas Vega

We initiate a systematic investigation of endomorphisms of graph C*-algebras C*(E), extending several known results on endomorphisms of the Cuntz algebras O_n. Most but not all of this study is focused on endomorphisms which permute the…

Operator Algebras · Mathematics 2013-01-11 Roberto Conti , Jeong Hee Hong , Wojciech Szymanski

We introduce the Exel-Pardo $*$-algebra $\mathrm{EP}_R(G,\Lambda)$ associated to a self-similar $k$-graph $(G,\Lambda,\varphi)$. We prove the $\mathbb{Z}^k$-graded and Cuntz-Krieger uniqueness theorems for such algebras and investigate…

Rings and Algebras · Mathematics 2023-08-22 Hossein Larki

In this paper we generalize the notion of a $k$-graph into (countable) infinite rank. We then define our $C^*$-algebra in a similar way as in $k$-graph $C^*$-algebras. With this construction we are able to find analogues to the Gauge…

Operator Algebras · Mathematics 2022-02-18 Tim Schenkel

We show that for a sofic shift Lambda, Matsumoto's C*-algebra O_Lambda is isomorphic to the Cuntz-Krieger algebra of the left Krieger cover graph of Lambda.

Operator Algebras · Mathematics 2007-05-23 Toke Meier Carlsen