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Related papers: Graph inverse semigroups and Leavitt path algebras

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An ultragraph gives rise to a labelled graph with some particular properties. In this paper we describe the algebras associated to such labelled graphs as groupoid algebras. More precisely, we show that the known groupoid algebra…

Rings and Algebras · Mathematics 2020-09-04 Gilles G. de Castro , Daniel Gonçalves , Daniel W. van Wyk

Given any directed graph E one can construct a graph inverse semigroup G(E), where, roughly speaking, elements correspond to paths in the graph. In this paper we study the semigroup-theoretic structure of G(E). Specifically, we describe the…

Group Theory · Mathematics 2016-07-27 Zachary Mesyan , J. D. Mitchell

In this paper we introduce an inverse semigroup $\mathcal{S}(E,C)$ associated to a separated graph $(E,C)$ and describe its internal structure. In particular we show that it is strongly $E^*$-unitary and can be realized as a partial…

Operator Algebras · Mathematics 2025-06-03 Pere Ara , Alcides Buss , Ado Dalla Costa

We achieve an extremely useful description (up to isomorphism) of the Leavitt path algebra $L_K(E)$ of a finite graph $E$ with coefficients in a field $K$ as a direct sum of matrix rings over $K$, direct sum with a corner of the Leavitt…

Rings and Algebras · Mathematics 2019-02-12 Gene Abrams , T. G. Nam

For any graph inverse semigroup $G(E)$ we describe subsemigroups $D^0=D\cup\{0\}$ and $J^0=J\cup\{0\}$ of $G(E)$ where $D$ and $J$ are arbitrary $\mathcal{D}$-class and $\mathcal{J}$-class of $G(E)$, respectively. In particular, we prove…

Group Theory · Mathematics 2019-04-23 Serhii Bardyla

We generalize the Li-Yang notion of self-similar $k$-graph $(G,\Lambda)$ and its $C^*$-algebra $\mathcal{O}_{G,\Lambda}$ to any finitely aligned $k$-graph $\Lambda$. We then introduce an inverse semigroup model for $\mathcal{O}_{G,\Lambda}$…

Operator Algebras · Mathematics 2024-11-22 Hossein Larki

The graph groupoids of directed graphs are topologically isomorphic if and only if there is a diagonal-preserving ring *-isomorphism between the Leavitt path algebras.

Rings and Algebras · Mathematics 2016-04-05 Jonathan H. Brown , Lisa Orloff Clark , Astrid an Huef

The geometry of inverse semigroups is a natural topic of study, motivated both from within semigroup theory and by applications to the theory of non-commutative $C^*$-algebras. We study the relationship between the geometry of an inverse…

Group Theory · Mathematics 2025-12-04 Mark Kambites , Nóra Szakács

We prove an algebraic version of the Gauge-Invariant Uniqueness Theorem, a result which gives information about the injectivity of certain homomorphisms between ${\mathbb Z}$-graded algebras. As our main application of this theorem, we…

Rings and Algebras · Mathematics 2008-02-04 G. Abrams , P. N. Ánh , A. Louly , E. Pardo

In this paper, we give a complete characterization of Leavitt path algebras which are graded $\Sigma $-$V$ rings, that is, rings over which a direct sum of arbitrary copies of any graded simple module is graded injective. Specifically, we…

Rings and Algebras · Mathematics 2017-10-19 Roozbeh Hazrat , Kulumani M. Rangaswamy , Ashish K. Srivastava

We describe a special class of representations of an inverse semigroup S on Hilbert's space which we term "tight". These representations are supported on a subset of the spectrum of the idempotent semilattice of S, called the "tight…

Operator Algebras · Mathematics 2008-06-25 Ruy Exel

We develop a technique to show the Morita equivalence of certain subrings of a ring with local units. We then apply this technique to develop conditions that are sufficient to show the Morita equivalence of subalgebras induced by partial…

Rings and Algebras · Mathematics 2025-03-11 Allen Zhang

We prove Leavitt path algebra versions of the two uniqueness theorems of graph C*-algebras. We use these uniqueness theorems to analyze the ideal structure of Leavitt path algebras and give necessary and sufficient conditions for their…

Operator Algebras · Mathematics 2007-05-23 Mark Tomforde

We introduce a notion of ideal-related K-theory for rings, and use it to prove that if two complex Leavitt path algebras are Morita equivalent (respectively, isomorphic), then the ideal-related K-theories (respectively, the unital…

Operator Algebras · Mathematics 2012-12-17 Efren Ruiz , Mark Tomforde

The aim of this work is the description of the isomorphism classes of all Leavitt path algebras coming from graphs satisfying Condition (Sing) with up to three vertices. In particular, this classification recovers the one achieved by Abrams…

Inspired by results for graph $C^*$-algebras, we investigate connections between the ideal structure of an inverse semigroup $S$ and that of its tight $C^*$-algebra by relating ideals in $S$ to certain open invariant sets in the associated…

Operator Algebras · Mathematics 2019-01-29 Scott M. LaLonde , David Milan , Jamie Scott

The unions of directed graphs are the simplest examples of pushouts of directed graphs. The conditions under which they contravariantly induce surjective gauge-equivariant pullbacks of graph C*-algebras have been well studied and vastly…

Rings and Algebras · Mathematics 2025-07-18 Piotr M. Hajac , Mariusz Tobolski

We relate two conjectures which have been raised for classification of Leavitt path algebras. For purely infinite simple unital Leavitt path algebras, it is conjectured that K_0 classifies them completely. For arbitrary Leavitt path…

Rings and Algebras · Mathematics 2012-04-17 R. Hazrat

Associating graph algebras to directed graphs leads to both covariant and contravariant functors from suitable categories of graphs to the category k-Alg of algebras and algebra homomorphisms. As both functors are often used at the same…

Rings and Algebras · Mathematics 2026-04-30 Gilles G. de Castro , Francesco D'Andrea , Piotr M. Hajac

The semidirect product of a finitely generated group dual with the symmetric group can be described through so-called group-theoretical categories of partitions (covers only a special case; due to Raum--Weber, 2015) and skew categories of…

Quantum Algebra · Mathematics 2022-03-25 Daniel Gromada