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A sense of direction is an edge labeling on graphs that follows a globally consistent scheme and is known to considerably reduce the complexity of several distributed problems. In this paper, we study a particular instance of sense of…

Discrete Mathematics · Computer Science 2007-05-23 R. S. C. Leao , V. C. Barbosa

In this article we give an algorithm for determining the generators and relations for the rings of semi-invariant functions on irreducible components of representation spaces for gentle string algebras. These rings of semi-invariants turn…

Representation Theory · Mathematics 2011-06-07 Andrew T. Carroll , Jerzy Weyman

A class $\mathcal{G}$ of graphs is hereditary if it is closed under taking induced subgraphs. We investigate the edge-add class, $\mathcal{G}^{\mathrm{add}}$, consisting of graphs that can be made members of $\mathcal{G}$ by adding at most…

Combinatorics · Mathematics 2026-04-10 Jagdeep Singh , Vaidy Sivaraman

This paper is the first from serial papers that provide constructive characterizations for classes of bidirected graphs known as radials and semiradials. In this paper, we provide constructive characterizations for five principle classes of…

Combinatorics · Mathematics 2020-01-03 Nanao Kita

The commuting graph of a group $G$ is the graph whose vertices are the elements of $G$, two distinct vertices joined if they commute. Our purpose in this paper is twofold: we discuss the computational problem of deciding whether a given…

Group Theory · Mathematics 2025-07-29 V. Arvind , Xuanlong Ma , Peter J. Cameron , Natalia V. Maslova

A network can be analyzed at different topological scales, ranging from single nodes to motifs, communities, up to the complete structure. We propose a novel intermediate-level topological analysis that considers non-overlapping subgraphs…

Computational Physics · Physics 2009-11-13 Lucas Antiqueira , Luciano da Fontoura Costa

We investigate the structure of conformally rigid graphs. Graphs are conformally rigid if introducing edge weights cannot increase (decrease) the second (last) eigenvalue of the Graph Laplacian. Edge-transitive graphs and distance-regular…

Combinatorics · Mathematics 2025-06-26 João Gouveia , Stefan Steinerberger , Rekha R. Thomas

We generalize the fundamental graph-theoretic notion of chordality for higher dimensional simplicial complexes by putting it into a proper context within homology theory. We generalize some of the classical results of graph chordality to…

Combinatorics · Mathematics 2015-10-29 Karim A. Adiprasito , Eran Nevo , Jose A. Samper

In a recent paper, Chernikov and Starchenko prove that graphs defined in distal theories have strong regularity properties, generalizing previous results about graphs defined by semi-algebraic relations. We give a shorter, purely…

Logic · Mathematics 2015-08-18 Pierre Simon

In this paper, motivated by a question posed in \cite{AH}, we introduce strongly biconvex graphs as a subclass of weakly chordal and bipartite graphs. We give a linear time algorithm to find an induced matching for such graphs and we prove…

Commutative Algebra · Mathematics 2019-05-08 Sara Saeedi Madani , Dariush Kiani

A graph is called chordal if it forbids induced cycles of length 4 or more. In this paper, we attempt to identify the non-nilpotent groups whose power graph is a chordal graph (this question was raised by Cameron in [4]). In this direction,…

Group Theory · Mathematics 2023-10-09 Pallabi Manna , Ranjit Mehatari

Let G be a finite simple graph. From the pioneering work of R. P. Stanley it is known that the cycle matroid of G is supersolvable iff G is chordal (rigid): this is another way to read Dirac's theorem on chordal graphs. Chordal binary…

Combinatorics · Mathematics 2007-05-23 Raul Cordovil , David Forge , Sulamita Klein

We collect some general results on graph limits associated to hereditary classes of graphs. As examples, we consider some classes defined by forbidden subgraphs and some classes of intersection graphs, including triangle-free graphs,…

Combinatorics · Mathematics 2013-03-29 Svante Janson

A T-graph (a special case of a chordal graph) is the intersection graph of connected subtrees of a suitable subdivision of a fixed tree T . We deal with the isomorphism problem for T-graphs which is GI-complete in general - when T is a part…

Discrete Mathematics · Computer Science 2022-03-01 Deniz Ağaoğlu Çağırıcı , Petr Hliněný

Necessary and sufficient conditions for a finite connected graph with a strict partial order on vertices to be a combinatorial invariant of pseudoharmonic function are obtained.

General Topology · Mathematics 2009-10-20 Yevgen Polulyakh , Iryna Yurchuk

The toughness of a graph $G$ is defined as the largest real number $t$ such that for any set $S\subseteq V(G)$ such that $G-S$ is disconnected, $S$ has at least $t$ times more elements than $G-S$ has components (unless $G$ is complete, in…

Combinatorics · Mathematics 2026-03-06 J. Pascal Gollin , Martin Milanič , Laura Ogrin

This paper establishes connections between the structure of a semigroup and the minimum spans of distance labellings of its Cayley graphs. We show that certain general restrictions on the minimum spans are equivalent to the semigroup being…

Combinatorics · Mathematics 2015-09-04 Andrei Kelarev , Charl Ras , Sanming Zhou

Introduced the quantitative measure of the structural complexity of the graph (complex network, etc.) based on a procedure similar to the renormalization process, considering the difference between actual and averaged graph structures on…

Physics and Society · Physics 2024-06-05 A. A. Snarskii

Intersection graphs are very important in both theoretical as well as application point of view. Depending on the geometrical representation, different type of intersection graphs are defined. Among them interval, circular-arc, permutation,…

Discrete Mathematics · Computer Science 2014-04-23 Madhumangal Pal

We introduce a class of chordal graphs called ($d_1$,$d_2$,$\dots$,$d_q$)-trees. A graph belongs to this class if and only if its clique complex is sequentially Cohen-Macaulay, providing a complete classification of all sequentially…

Commutative Algebra · Mathematics 2025-10-14 Chwas Ahmed , Amir Mafi , Mohammed Rafiq Namiq
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