English
Related papers

Related papers: Commuting Graphs of Boundedly Generated Semigroups

200 papers

Daligault, Rao and Thomass\'e asked whether every hereditary graph class that is well-quasi-ordered by the induced subgraph relation has bounded clique-width. Lozin, Razgon and Zamaraev (JCTB 2017+) gave a negative answer to this question,…

Combinatorics · Mathematics 2017-11-27 Konrad K. Dabrowski , Vadim V. Lozin , Daniël Paulusma

A natural way of increasing our understanding of NP-complete graph problems is to restrict the input to a special graph class. Classes of $H$-free graphs, that is, graphs that do not contain some graph $H$ as an induced subgraph, have…

Data Structures and Algorithms · Computer Science 2022-04-19 Christoph Brause , Petr Golovach , Barnaby Martin , Daniël Paulusma , Siani Smith

A graph is $H$-free if it has no induced subgraph isomorphic to $H$. We continue a study into the boundedness of clique-width of subclasses of perfect graphs. We identify five new classes of $H$-free split graphs whose clique-width is…

Discrete Mathematics · Computer Science 2015-09-16 Andreas Brandstädt , Konrad K. Dabrowski , Shenwei Huang , Daniël Paulusma

Amit and Linial showed that a random lift of a graph with minimum degree $\delta\ge3$ is asymptotically almost surely $\delta$-connected, and mentioned the problem of estimating this probability as a function of the degree of the lift. We…

Discrete Mathematics · Computer Science 2017-03-23 Shashwat Silas

Given two graphs $H_1$ and $H_2$, a graph $G$ is $(H_1,H_2)$-free if it contains no subgraph isomorphic to $H_1$ or $H_2$. We continue a recent study into the clique-width of $(H_1,H_2)$-free graphs and present three new classes of…

Discrete Mathematics · Computer Science 2015-01-14 Konrad K. Dabrowski , Shenwei Huang , Daniël Paulusma

In this paper we consider endomorphisms of an undirected cycle graph from Semigroup Theory perspective. Our main aim is to present a process to determine sets of generators with minimal cardinality for the monoids $wEnd(C_n)$ and $End(C_n)$…

Rings and Algebras · Mathematics 2023-10-09 Ilinka Dimitrova , Vítor H. Fernandes , Jörg Koppitz , Teresa M. Quinteiro

Let $G$ be a finite group. The \textit{commuting/nilpotent/solvable conjugacy class graph} ($\Gamma_{CCC}(G)$, $\Gamma_{NCC}(G)$, or $\Gamma_{SCC}(G)$) is a simple graph whose vertex set consists of all non-central conjugacy classes of $G$.…

Group Theory · Mathematics 2025-04-02 Papi Ray , Sonakshee Arora

We consider the problems of finding optimal identifying codes, (open) locating-dominating sets and resolving sets of an interval or a permutation graph. In these problems, one asks to find a subset of vertices, normally called a…

Discrete Mathematics · Computer Science 2017-07-17 Florent Foucaud , George B. Mertzios , Reza Naserasr , Aline Parreau , Petru Valicov

We have generalised the concept of graph states to what we have called mixed graph states, which we define in terms of mixed graphs, that is graphs with both directed and undirected edges, as the density matrix stabilized by the associated…

Quantum Physics · Physics 2016-03-17 Constanza Riera , Ramij Rahaman , Matthew G. Parker

Let $G=\Gamma(S)$ be a semigroup graph, i.e., a zero-divisor graph of a semigroup $S$ with zero element 0. For any adjacent vertices $x, y$ in $G$, denote $C(x,y)={z\in V(G) | N(z)={x,y}}$. Assume that in $G$ there exist two adjacent…

Rings and Algebras · Mathematics 2018-04-24 Li Chen , Tongsuo Wu

A set $D$ of vertices in an isolate-free graph $G$ is a semitotal dominating set of $G$ if $D$ is a dominating set of $G$ and every vertex in $D$ is within distance $2$ from another vertex of $D$.The semitotal domination number of $G$ is…

Combinatorics · Mathematics 2021-07-06 Saeid Alikhani , Hassan Zaherifar

We investigate which chordal graphs have a representation as intersection graphs of pseudosegments. For positive we have a construction which shows that all chordal graphs that can be represented as intersection graph of subpaths on a tree…

Combinatorics · Mathematics 2008-09-12 Cornelia Dangelmayr , Stefan Felsner , William T. Trotter

A graph $\Gamma$ is said to be a semi-Cayley graph over a group $G$ if it admits $G$ as a semiregular automorphism group with two orbits of equal size. We say that $\Gamma$ is normal if $G$ is a normal subgroup of ${\rm Aut}(\Gamma)$. We…

Combinatorics · Mathematics 2020-04-22 Majid Arezoomand , Mohsen Ghasemi

Quasi-median graphs are a tool commonly used by evolutionary biologists to visualise the evolution of molecular sequences. As with any graph, a quasi-median graph can contain cut vertices, that is, vertices whose removal disconnect the…

Combinatorics · Mathematics 2014-12-23 Sven Herrmann , Vincent Moulton

A quasi-automatic semigroup is defined by a finite set of generators, a rational (regular) set of representatives, such that if a is a generator or neutral, then the graph of right multiplication by a on the set of representatives is a…

Group Theory · Mathematics 2019-06-12 Benjamin Blanchette , Christian Choffrut , Christophe Reutenauer

We give a geometric approach to groups defined by automata via the notion of enriched dual of an inverse transducer. Using this geometric correspondence we first provide some finiteness results, then we consider groups generated by the dual…

Group Theory · Mathematics 2015-03-13 Daniele D'Angeli , Emanuele Rodaro

Let $G$ be a non-abelian group. The non-commuting graph $\mathcal{A}_G$ of $G$ is defined as the graph whose vertex set is the non-central elements of $G$ and two vertices are joint if and only if they do not commute. In a finite simple…

Group Theory · Mathematics 2009-03-05 A. Abdollahi , A. Azad , A. Mohammadi Hassanabadi , M. Zarrin

A mixed dihedral group is a group $H$ with two disjoint subgroups $X$ and $Y$, each elementary abelian of order $2^n$, such that $H$ is generated by $X\cup Y$, and $H/H'\cong X\times Y$. In this paper, for each $n\geq 2$, we construct a…

Combinatorics · Mathematics 2023-03-02 Daniel R. Hawtin , Jin-Xin Zhou , Cheryl E. Praeger

In the study of full bubble model graphs of bounded clique-width and bounded linear clique-width, we determined complete sets of forbidden induced subgraphs, that are minimal in the class of full bubble model graphs. In this note, we show…

Discrete Mathematics · Computer Science 2014-01-29 Daniel Meister , Udi Rotics

We obtain the scaling limits of random graphs drawn uniformly in three families of intersection graphs: permutation graphs, circle graphs, and unit interval graphs. The two first families typically generate dense graphs, in these cases we…

Probability · Mathematics 2024-02-12 Frédérique Bassino , Mathilde Bouvel , Valentin Féray , Lucas Gerin , Adeline Pierrot