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k-graphs are higher-rank analogues of directed graphs which were first developed to provide combinatorial models for operator algebras of Cuntz-Krieger type. Here we develop the theory of covering spaces for k-graphs, obtaining a…

Operator Algebras · Mathematics 2008-05-23 David Pask , John Quigg , Iain Raeburn

Topology identification and inference of processes evolving over graphs arise in timely applications involving brain, transportation, financial, power, as well as social and information networks. This chapter provides an overview of graph…

Signal Processing · Electrical Eng. & Systems 2025-12-12 Gonzalo Mateos , Yanning Shen , Georgios B. Giannakis , Ananthram Swami

We study Sims-Yeend's product system C*-algebras and topological higher-rank graph C*-algebras by Yeend. We give a relation between Katsura's Cuntz-Pimsner covariance and Sims-Yeend's one by a direct approach and an explicit form of the…

Operator Algebras · Mathematics 2010-10-15 Shinji Yamashita

A theorem is proved to verify incremental stability of a feedback system via a homotopy from a known incrementally stable system. A first corollary of that result is that incremental stability may be verified by separation of Scaled…

Optimization and Control · Mathematics 2024-12-03 Thomas Chaffey , Andrey Kharitenko , Fulvio Forni , Rodolphe Sepulchre

Properties of the `$k$-equivalent' graph families constructed in Cai, F\"{u}rer and Immerman, and Evdokimov and Ponomarenko are analysed relative the the recursive $k$-dim WL method. An extension to the recursive $k$-dim WL method is…

Combinatorics · Mathematics 2011-01-28 B. L. Douglas

The symmetric tensor power of graphs is introduced and its fundamental properties are explored. A wide range of intriguing phenomena occur when one considers symmetric tensor powers of familiar graphs. A host of open questions are…

In 1985, Golumbic and Scheinerman established an equivalence between comparability graphs and containment graphs, graphs whose vertices represent sets, with edges indicating set containment. A few years earlier, McMorris and Zaslavsky…

Combinatorics · Mathematics 2025-03-31 Ketai Chen , Jared DeLeo , Owen Henderschedt

Tensor models and, more generally, group field theories are candidates for higher-dimensional quantum gravity, just as matrix models are in the 2d setting. With the recent advent of a 1/N-expansion for coloured tensor models, more focus has…

General Relativity and Quantum Cosmology · Physics 2013-05-30 James P. Ryan

The presented work focuses on problems from determinant theory, set theory and topology. The term graph is the binding element that connects these problems. Graphs are distinguished by their geometrical simplicity, which helps in showing…

History and Overview · Mathematics 2024-12-24 Ágnes Cseh

It is known that isomorphisms of graph Jacobians induce cyclic bijections on the associated graphs. We characterize when such cyclic bijections can be strengthened to graph isomorphisms, in terms of an easily computed divisor. The result…

Combinatorics · Mathematics 2023-07-25 Sarah Griffith

We provide inverse semigroup and groupoid models for the Toeplitz and Cuntz-Krieger algebras of finitely aligned higher-rank graphs. Using these models, we prove a uniqueness theorem for the Cuntz-Krieger algebra.

Operator Algebras · Mathematics 2007-05-23 Cynthia Farthing , Paul S. Muhly , Trent Yeend

Some families of graphs, such as the n-cubes and Sierpinski gaskets, are self-similar. In this paper we show how such recursive structure can be used systematically to prove isoperimetric theorems.

Combinatorics · Mathematics 2016-10-10 L. H. Harper

Analogues of Ramsey's Theorem for infinite structures such as the rationals or the Rado graph have been known for some time. In this context, one looks for optimal bounds, called degrees, for the number of colors in an isomorphic…

Combinatorics · Mathematics 2022-06-03 Natasha Dobrinen

$O(N)$ invariants are the observables of real tensor models. We use regular colored graphs to represent these invariants, the valence of the vertices of the graphs relates to the tensor rank. We enumerate $O(N)$ invariants as $d$-regular…

Mathematical Physics · Physics 2022-11-15 Remi C. Avohou , Joseph Ben Geloun , Nicolas Dub

Let $G$ be a finite group. A number of graphs with the vertex set $G$ have been studied, including the power graph, enhanced power graph, and commuting graph. These graphs form a hierarchy under the inclusion of edge sets, and it is useful…

Combinatorics · Mathematics 2021-12-07 G. Arunkumar , Peter J. Cameron , Rajat Kanti Nath , Lavanya Selvaganesh

Topological metrics of graphs provide a natural way to describe the prominent features of various types of networks. Graph metrics describe the structure and interplay of graph edges and have found applications in many scientific fields. In…

Data Structures and Algorithms · Computer Science 2018-06-21 Loukianos Spyrou , Javier Escudero

We construct explicit generators for the higher scissors congruence K-theory of the line. We use this to derive an explicit generating set for the homology of the group of interval exchange transformations. Our proof makes use of an…

K-Theory and Homology · Mathematics 2025-07-08 Ezekiel Lemann

We generalize the concept of token graphs to obtain supertoken graphs. In the latter case, there can be more than one token in a vertex. We formally define supertoken graphs and establish their basic properties. Moreover, we provide some…

Combinatorics · Mathematics 2026-04-08 Mónica A. Reyes , Cristina Dalfó , Miquel Àngel Fiol

In this work we consider the topological analysis of symbolic formal systems in the framework of network theory. In particular we analyse the network extracted by Principia Mathematica of B. Russell and A.N. Whitehead, where the vertices…

Physics and Society · Physics 2011-09-09 A. P. Masucci

In this note, we introduce a new method for constructing graphs with high chromatic number and small clique. Indeed, via this method, we present a new proof for the well-known Kneser's conjecture.

Combinatorics · Mathematics 2017-09-12 Hamid Reza Daneshpajouh