Results 31 to 40 of about 1,634 (112)
Conflict-Free Vertex-Connections of Graphs
Discussiones Mathematicae Graph Theory, 2020 A path in a vertex-colored graph is called conflict-free if there is a color used on exactly one of its vertices. A vertex-colored graph is said to be conflict-free vertex-connected if any two vertices of the graph are connected by a conflict-free path ...
Li Xueliang +5 more
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Some results on the total proper k-connection number
Open Mathematics, 2022 In this paper, we first investigate the total proper connection number of a graph GG according to some constraints of G¯\overline{G}. Next, we investigate the total proper connection numbers of graph GG with large clique number ω(G)=n−s\omega \left(G)=n ...
Ma Yingbin, Zhang Hui
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Homomorphisms and related contractions of graphs
International Journal of Mathematics and Mathematical Sciences, Volume 11, Issue 1, Page 95-100, 1988., 1986 For every homomorphism ϕ of a graph G there exists a contraction θϕ on , the complement of G. Here we study the graph equation . In the course of our work we show that Hadwiger′s Conjecture is true for every self‐complementary graph.
Robert D. Girse, Richard A. Gillman
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Distinguishing Cartesian Products of Countable Graphs
Discussiones Mathematicae Graph Theory, 2017 The distinguishing number D(G) of a graph G is the minimum number of colors needed to color the vertices of G such that the coloring is preserved only by the trivial automorphism.
Estaji Ehsan +4 more
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Trees with Distinguishing Index Equal Distinguishing Number Plus One
Discussiones Mathematicae Graph Theory, 2020 The distinguishing number (index) D(G) (D′ (G)) of a graph G is the least integer d such that G has an vertex (edge) labeling with d labels that is preserved only by the trivial automorphism.
Alikhani Saeid +3 more
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Complexity of locally-injective homomorphisms to tournaments [PDF]
Discrete Mathematics & Theoretical Computer Science, 2018 For oriented graphs $G$ and $H$, a homomorphism $f: G \rightarrow H$ is locally-injective if, for every $v \in V(G)$, it is injective when restricted to some combination of the in-neighbourhood and out-neighbourhood of $v$.
Stefan Bard +4 more
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Homomorphisms of complete n‐partite graphs
International Journal of Mathematics and Mathematical Sciences, Volume 9, Issue 1, Page 193-195, 1986., 1985 It is shown that for every homomorphism ϕ of a graph G there exists a contraction θϕ on , the complement of G, such that if and only if G is a complete n‐partite graph.
Robert D. Girse
wiley +1 more source
Rainbow Connection Number of Graphs with Diameter 3
Discussiones Mathematicae Graph Theory, 2017 A path in an edge-colored graph G is rainbow if no two edges of the path are colored the same. The rainbow connection number rc(G) of G is the smallest integer k for which there exists a k-edge-coloring of G such that every pair of distinct vertices of G
Li Hengzhe, Li Xueliang, Sun Yuefang
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Generalized Ramsey numbers for paths in 2‐chromatic graphs
International Journal of Mathematics and Mathematical Sciences, Volume 9, Issue 2, Page 273-276, 1986., 1985 Chung and Liu have defined the d‐chromatic Ramsey number as follows. Let 1 ≤ d ≤ c and let . Let 1, 2, …, t be the ordered subsets of d colors chosen from c distinct colors. Let G1, G2, …, Gt be graphs. The d‐chromatic Ramsey number denoted by is defined as the least number p such that, if the edges of the complete graph Kp are colored in any fashion ...
R. Meenakshi, P. S. Sundararaghavan
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Discussiones Mathematicae Graph Theory, 2020 If S = (a1, a2, . . .) is a non-decreasing sequence of positive integers, then an S-packing coloring of a graph G is a partition of V (G) into sets X1, X2, . . .
Brešar Boštjan +3 more
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