Results 11 to 20 of about 11,796 (253)

Graphs of low chordality [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2005
The chordality of a graph with at least one cycle is the length of the longest induced cycle in it. The odd (even) chordality is defined to be the length of the longest induced odd (even) cycle in it. Chordal graphs have chordality at most 3.
Sunil Chandran   +2 more
doaj   +6 more sources

On chordal phylogeny graphs [PDF]

open access: yesDiscrete Applied Mathematics, 2021
An acyclic digraph each vertex of which has indegree at most $i$ and outdegree at most $j$ is called an $(i, j)$ digraph for some positive integers $i$ and $j$. Lee {\it et al.} (2017) studied the phylogeny graphs of $(2, 2)$ digraphs and gave sufficient conditions and necessary conditions for $(2, 2)$ digraphs having chordal phylogeny graphs.
Soogang Eoh, Suh-Ryung Kim
openaire   +2 more sources

Characterizing 2-Trees Relative to Chordal and Series-Parallel Graphs

open access: yesTheory and Applications of Graphs, 2021
The 2-connected 2-tree graphs are defined as being constructible from a single 3-cycle by recursively appending new degree-2 vertices so as to form 3-cycles that have unique edges in common with the existing graph.
Terry McKee
doaj   +1 more source

Further results on Hendry's Conjecture [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2022
Recently, a conjecture due to Hendry was disproved which stated that every Hamiltonian chordal graph is cycle extendible. Here we further explore the conjecture, showing that it fails to hold even when a number of extra conditions are imposed.
Manuel Lafond   +2 more
doaj   +1 more source

Algorithmic Aspects of Some Variations of Clique Transversal and Clique Independent Sets on Graphs

open access: yesAlgorithms, 2021
This paper studies the maximum-clique independence problem and some variations of the clique transversal problem such as the {k}-clique, maximum-clique, minus clique, signed clique, and k-fold clique transversal problems from algorithmic aspects for k ...
Chuan-Min Lee
doaj   +1 more source

Hyperbolicity and Chordality of a Graph [PDF]

open access: yesThe Electronic Journal of Combinatorics, 2011
Let $G$ be a connected graph with the usual shortest-path metric $d$. The graph $G$ is $\delta$-hyperbolic provided for any vertices $x,y,u,v$ in it, the two larger of the three sums $d(u,v)+d(x,y),d(u,x)+d(v,y)$ and $d(u,y)+d(v,x)$ differ by at most $2\delta.$ The graph $G$ is $k$-chordal provided it has no induced cycle of length greater than $k ...
Yaokun Wu, Chengpeng Zhang
openaire   +2 more sources

An Edge-Signed Generalization of Chordal Graphs, Free Multiplicities on Braid Arrangements, and Their Characterizations [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2009
In this article, we propose a generalization of the notion of chordal graphs to signed graphs, which is based on the existence of a perfect elimination ordering for a chordal graph. We give a special kind of filtrations of the generalized chordal graphs,
Takuro Abe, Koji Nuida, Yasuhide Numata
doaj   +1 more source

Properties and Recognition of Atom Graphs

open access: yesAlgorithms, 2022
The atom graph of a connected graph is a graph whose vertices are the atoms obtained by clique minimal separator decomposition of this graph, and whose edges are the edges of all its atom trees.
Geneviève Simonet, Anne Berry
doaj   +1 more source

Axiomatic characterizations of Ptolemaic and chordal graphs [PDF]

open access: yesOpuscula Mathematica, 2023
The interval function and the induced path function are two well studied class of set functions of a connected graph having interesting properties and applications to convexity, metric graph theory. Both these functions can be framed as special instances
Manoj Changat   +2 more
doaj   +1 more source

Branchwidth of chordal graphs [PDF]

open access: yesDiscrete Applied Mathematics, 2009
This paper revisits the ‘branchwidth territories' of Kloks, Kratochvíl and Müller [T. Kloks, J. Kratochvíl, H. Müller, New branchwidth territories, in: 16th Ann. Symp. on Theoretical Aspect of Computer Science, STACS, in: Lecture Notes in Computer Science, vol. 1563, 1999, pp.
Paul, Christophe, Telle, Jan Arne
openaire   +1 more source

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