Results 21 to 30 of about 1,930 (230)
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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Algorithmic Aspects of Secure Connected Domination in Graphs
Discussiones Mathematicae Graph Theory, 2021 Let G = (V, E) be a simple, undirected and connected graph. A connected dominating set S ⊆ V is a secure connected dominating set of G, if for each u ∈ V \ S, there exists v ∈ S such that (u, v) ∈ E and the set (S \ {v}) ∪ {u} is a connected dominating ...
Kumar Jakkepalli Pavan +1 more
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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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$b$-vectors of chordal graphs [PDF]
Journal of Commutative Algebra, 2020 19 pages. 4 figures.
Montejano, Luis Pedro +1 more
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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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Discrete Mathematics, 1994 AbstractWe introduce the closed-neighborhood intersection multigraph as a useful multigraph version of the square of a graph. We characterize those multigraphs which are squares of chordal graphs and include an algorithm to go from the squared chordal graph back to its (unique!) square root. This becomes particularly simple in the case of k-trees, with
Frank Harary, Terry A. McKee
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Recognition of chordal graphs and cographs which are Cover-Incomparability graphs [PDF]
Discrete Mathematics & Theoretical Computer ScienceCover-Incomparability graphs (C-I graphs) are an interesting class of graphs from posets. A C-I graph is a graph from a poset $P=(V,\le)$ with vertex set $V$, and the edge-set is the union of edge sets of the cover graph and the incomparability graph of ...
Arun Anil, Manoj Changat
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Graph isomorphism completeness for chordal bipartite graphs and strongly chordal graphs
Discrete Applied Mathematics, 2005 AbstractThis paper deals with the graph isomorphism (GI) problem for two graph classes: chordal bipartite graphs and strongly chordal graphs. It is known that GI problem is GI complete even for some special graph classes including regular graphs, bipartite graphs, chordal graphs, comparability graphs, split graphs, and k-trees with unbounded k.
Ryuhei Uehara +2 more
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On chordal graph and line graph squares [PDF]
Discrete Applied Mathematics, 2018 In this work we investigate the chordality of squares and line graph squares of graphs. We prove a sufficient condition for the chordality of squares of graphs not containing induced cycles of length at least five. Moreover, we characterize the chordality of graph squares by forbidden subgraphs.
Robert Scheidweiler +1 more
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Carpathian Journal of Mathematics, 2021 Triangulated graphs have many interesting properties (perfection, recognition algorithms, combinatorial optimization algorithms with linear complexity). Hyper-triangulated graphs are those where each induced subgraph has a hyper-simplicial vertex. In this paper we give the characterizations of hyper-triangulated graphs using an ordering of vertices and
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