Results 51 to 60 of about 1,772 (132)

Double domination in maximal outerplanar graphs

open access: yes, 2021
In a graph $G$, a vertex dominates itself and its neighbors. A subset $S\subseteq V(G)$ is said to be a double dominating set of $G$ if $S$ dominates every vertex of $G$ at least twice. The double domination number $ _{\times 2}(G)$ is the minimum cardinality of a double dominating set of $G$.
openaire   +2 more sources

Symmetry breaking in planar and maximal outerplanar graphs [PDF]

open access: yesDiscrete Mathematics, Algorithms and Applications, 2019
The distinguishing number (index) [Formula: see text] ([Formula: see text]) of a graph [Formula: see text] is the least integer [Formula: see text] such that [Formula: see text] has a vertex (edge) labeling with [Formula: see text] labels that is preserved only by a trivial automorphism.
Alikhani, Saeid, Soltani, Samaneh
openaire   +3 more sources

On the Hub Number of Ring Graphs and Their Behavior Under Graph Operations

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2025, Issue 1, 2025.
This study examines the hub number of ring graphs and investigates their behavior under operations such as union, intersection, and join. Different findings for this parameter are found for a variety of types of ring graphs, such as commutative ring graphs, path ring graphs, complete ring graphs, cycle ring graphs, and star ring graphs, for which the ...
Mohammed Alsharafi   +3 more
wiley   +1 more source

Self‐avoiding walks and polygons on hyperbolic graphs

open access: yesJournal of Graph Theory, Volume 106, Issue 3, Page 435-473, July 2024.
Abstract We prove that for the d $d$‐regular tessellations of the hyperbolic plane by k $k$‐gons, there are exponentially more self‐avoiding walks of length n $n$ than there are self‐avoiding polygons of length n $n$. We then prove that this property implies that the self‐avoiding walk is ballistic, even on an arbitrary vertex‐transitive graph ...
Christoforos Panagiotis
wiley   +1 more source

Random graphs embeddable in order‐dependent surfaces

open access: yesRandom Structures &Algorithms, Volume 64, Issue 4, Page 940-985, July 2024.
Abstract Given a ‘genus function’ g=g(n)$$ g=g(n) $$, we let Eg$$ {\mathcal{E}}^g $$ be the class of all graphs G$$ G $$ such that if G$$ G $$ has order n$$ n $$ (i.e., has n$$ n $$ vertices) then it is embeddable in a surface of Euler genus at most g(n)$$ g(n) $$.
Colin McDiarmid, Sophia Saller
wiley   +1 more source

A study of upper ideal relation graphs of rings

open access: yesAKCE International Journal of Graphs and Combinatorics
Let R be a ring with unity. The upper ideal relation graph [Formula: see text] of the ring R is the simple undirected graph whose vertex set is the set of all non-unit elements of R and two distinct vertices x, y are adjacent if and only if there exists ...
Barkha Baloda   +2 more
doaj   +1 more source

On tree decompositions whose trees are minors

open access: yesJournal of Graph Theory, Volume 106, Issue 2, Page 296-306, June 2024.
Abstract In 2019, Dvořák asked whether every connected graph G $G$ has a tree decomposition ( T , B ) $(T,{\rm{ {\mathcal B} }})$ so that T $T$ is a subgraph of G $G$ and the width of ( T , B ) $(T,{\rm{ {\mathcal B} }})$ is bounded by a function of the treewidth of G $G$.
Pablo Blanco   +5 more
wiley   +1 more source

Bipartite Minors [PDF]

open access: yes, 2013
We introduce a notion of bipartite minors and prove a bipartite analog of Wagner's theorem: a bipartite graph is planar if and only if it does not contain $K_{3,3}$ as a bipartite minor.
Chudnovsky, Maria   +4 more
core   +1 more source

Small Superpatterns for Dominance Drawing

open access: yes, 2013
We exploit the connection between dominance drawings of directed acyclic graphs and permutations, in both directions, to provide improved bounds on the size of universal point sets for certain types of dominance drawing and on superpatterns for certain ...
Bannister, Michael J.   +2 more
core   +1 more source

The product structure of squaregraphs

open access: yesJournal of Graph Theory, Volume 105, Issue 2, Page 179-191, February 2024.
Abstract A squaregraph is a plane graph in which each internal face is a 4‐cycle and each internal vertex has degree at least 4. This paper proves that every squaregraph is isomorphic to a subgraph of the semistrong product of an outerplanar graph and a path.
Robert Hickingbotham   +3 more
wiley   +1 more source

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