English
Related papers

Related papers: Fundamental groupoids of k-graphs

200 papers

A maniplex of rank n is a connected, n-valent, edge-coloured graph that generalises abstract polytopes and maps. If the automorphism group of a maniplex M partitions the vertex-set of M into k distinct orbits, we say that M is a k-orbit…

Combinatorics · Mathematics 2018-12-12 Daniel Pellicer , Primož Potočnik , Micael Toledo

The construction of the C*-algebra associated to a directed graph $E$ is extended to incorporate a family $C$ consisting of partitions of the sets of edges emanating from the vertices of $E$. These C*-algebras $C^*(E,C)$ are analyzed in…

Operator Algebras · Mathematics 2011-07-12 P. Ara , K. R. Goodearl

We calculate the ordered K_0-group of a graph C*-algebra and mention applications of this result to AF-algebras, states on the K_0-group of a graph algebra, and tracial states of graph algebras.

Operator Algebras · Mathematics 2007-05-23 Mark Tomforde

Topological quivers are generalizations of directed graphs in which the sets of vertices and edges are locally compact Hausdorff spaces. Associated to such a topological quiver Q is a C*-correspondence, and from this correspondence one may…

Operator Algebras · Mathematics 2007-05-23 Paul S. Muhly , Mark Tomforde

We introduce $C^*$-algebras associated with directed graphs, along with two generalizations of this concept, namely Exel-Pardo $C^*$-algebras associated with a self-similar action of a group on a directed graph, and the $C^*$-algebras…

Operator Algebras · Mathematics 2026-04-21 Pere Ara

We introduce graphical complexes of groups, which can be thought of as a generalisation of Coxeter systems with 1-dimensional nerves. We show that these complexes are strictly developable, and we equip the resulting Basic Construction with…

Group Theory · Mathematics 2020-04-20 Tomasz Prytuła

We develop a general diagrammatic theory of welded graphs, and provide an extension of Satoh's Tube map from welded graphs to ribbon surface-links. As a topological application, we obtain a complete link-homotopy classification of so-called…

Geometric Topology · Mathematics 2025-07-29 Benjamin Audoux , Jean-Baptiste Meilhan , Akira Yasuhara

The kernel of the natural projection of a graph product of groups onto their direct product is called the Cartesian subgroup of the graph product. This construction generalises commutator subgroups of right-angled Coxeter and Artin groups.…

Group Theory · Mathematics 2025-07-30 Fedor Vylegzhanin

In this paper, prime as well as primitive Kumjian-Pask algebras $\mathrm{KP}_R(\Lambda)$ of a row-finite $k$-graph $\Lambda$ over a unital commutative ring $R$ are completely characterized in graph-theoretic and algebraic terms. By applying…

Rings and Algebras · Mathematics 2017-01-04 Maryam Kashoul-Radjabzadeh , Hossein Larki , Abdolmohammad Aminpour

Path and boundary-path groupoids of finitely aligned higher-rank graphs are often constructed using either filters or graph morphisms. We generalise the graph morphism approach to finitely aligned P-graphs where (Q, P) is a weakly…

Rings and Algebras · Mathematics 2025-09-18 Lisa Orloff Clark , Malcolm Jones

Let $G$ be a group. We define the coprime graph of subgroups of $G$, denoted by $\mathcal P(G)$, is a graph whose vertex set is the set of all proper subgroups of $G$, and two distinct vertices are adjacent if and only if the order of the…

Group Theory · Mathematics 2015-12-08 R. Rajkumar , P. Devi

Time series clustering poses a significant challenge with diverse applications across domains. A prominent drawback of existing solutions lies in their limited interpretability, often confined to presenting users with centroids. In…

Machine Learning · Computer Science 2025-02-19 Paul Boniol , Donato Tiano , Angela Bonifati , Themis Palpanas

To each graph without loops and multiple edges we assign a family of rings. Categories of projective modules over these rings categorify $U^-_q(\mathfrak{g})$, where $\mathfrak{g}$ is the Kac-Moody Lie algebra associated with the graph.

Quantum Algebra · Mathematics 2025-01-23 Mikhail Khovanov , Aaron D. Lauda

We classify the gauge-invariant ideals in the C*-algebras of infinite directed graphs, and describe the quotients as graph algebras. We then use these results to identify the gauge-invariant primitive ideals in terms of the structural…

Operator Algebras · Mathematics 2007-05-23 Teresa Bates , Jeong Hee Hong , Iain Raeburn , Wojciech Szymanski

In this paper we define complex equivariant K-theory for actions of Lie groupoids using finite-dimensional vector bundles. For a Bredon-compatible Lie groupoid, this defines a periodic cohomology theory on the category of finite equivariant…

Algebraic Topology · Mathematics 2012-09-10 Jose Cantarero

In the analysis of large-scale network data, a fundamental operation is the comparison of observed phenomena to the predictions provided by null models: when we find an interesting structure in a family of real networks, it is important to…

Social and Information Networks · Computer Science 2021-02-26 Katherine Van Koevering , Austin R. Benson , Jon Kleinberg

We extend the the definition of Kumjian-Pask algebras to include algebras associated to finitely aligned higher-rank graphs. We show that these Kumjian-Pask algebras are universally defined and have a graded uniqueness theorem. We also…

Rings and Algebras · Mathematics 2015-12-22 Lisa Orloff Clark , Yosafat E. P. Pangalela

In this paper we continue the study of prime graphs of finite solvable groups. The prime graph, or Gruenberg-Kegel graph, of a finite group G has vertices consisting of the prime divisors of the order of G and an edge from primes p to q if…

Combinatorics · Mathematics 2022-10-26 Ziyu Huang , Thomas Michael Keller , Shane Kissinger , Wen Plotnick , Maya Roma

In this paper we complete the classification of topological symmetry groups for complete graphs $K_n$ by characterizing which $K_n$ can have a cyclic group, a dihedral group, or a subgroup of $D_m \times D_m$ where $m$ is odd, as its…

Geometric Topology · Mathematics 2014-12-24 Erica Flapan , Blake Mellor , Ramin Naimi , Michael Yoshizawa

A k-connected graph such that deleting any edge / deleting any vertex / contracting any edge results in a graph which is not k-connected is called minimally / critically / contraction-critically k-connected. These three classes play a…

Combinatorics · Mathematics 2011-01-13 Matthias Kriesell