Results 11 to 20 of about 756 (218)
On chordal phylogeny graphs [PDF]
Discrete 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
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Hyperbolicity and Chordality of a Graph [PDF]
The 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
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Branchwidth of chordal graphs [PDF]
Discrete 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
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Polynomial kernels for edge modification problems towards block and strictly chordal graphs [PDF]
Discrete Mathematics & Theoretical Computer ScienceWe consider edge modification problems towards block and strictly chordal graphs, where one is given an undirected graph $G = (V,E)$ and an integer $k \in \mathbb{N}$ and seeks to edit (add or delete) at most $k$ edges from $G$ to obtain a block graph or
Maël Dumas +3 more
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Minimal toughness in special graph classes [PDF]
Discrete Mathematics & Theoretical Computer Science, 2023 Let $t$ be a positive real number. A graph is called $t$-tough if the removal of any vertex set $S$ that disconnects the graph leaves at most $|S|/t$ components, and all graphs are considered 0-tough. The toughness of a graph is the largest $t$ for which
Gyula Y. Katona, Kitti Varga
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Discrete Applied Mathematics, 2003 A graph \(G=(V, E)\) is a chordal probe graph if there exists a partition \(V=P\cup N\) with a stable set \(N\) and a completion \(E'\subseteq\{uv : u\not= v\in N\}\) such that the graph \((V, E\cup E')\) is a chordal graph. Chordal probe graphs generalize probe interval graphs introduced by P. Zhang; see also [\textit{F. R. McMorris, C.
Martin Charles Golumbic +1 more
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Discrete Mathematics & Theoretical Computer Science, 2019 Slimness of a graph measures the local deviation of its metric from a tree metric. In a graph $G=(V,E)$, a geodesic triangle $\bigtriangleup(x,y,z)$ with $x, y, z\in V$ is the union $P(x,y) \cup P(x,z) \cup P(y,z)$ of three shortest paths connecting ...
Feodor F. Dragan, Abdulhakeem Mohammed
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Characterizing 2-Trees Relative to Chordal and Series-Parallel Graphs
Theory 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
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Capturing Logarithmic Space and Polynomial Time on Chordal Claw-Free Graphs [PDF]
Logical Methods in Computer Science, 2019 We show that the class of chordal claw-free graphs admits LREC$_=$-definable canonization. LREC$_=$ is a logic that extends first-order logic with counting by an operator that allows it to formalize a limited form of recursion.
Berit Grußien
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Graph Extremities Defined by Search Algorithms
Algorithms, 2010 Graph search algorithms have exploited graph extremities, such as the leaves of a tree and the simplicial vertices of a chordal graph. Recently, several well-known graph search algorithms have been collectively expressed as two generic algorithms called ...
Jean-Paul Bordat +3 more
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