Results 11 to 20 of about 10,088 (246)
The Ryjáček Closure and a Forbidden Subgraph
Discussiones Mathematicae Graph Theory, 2016 The Ryjáček closure is a powerful tool in the study of Hamiltonian properties of claw-free graphs. Because of its usefulness, we may hope to use it in the classes of graphs defined by another forbidden subgraph. In this note, we give a negative answer to
Saito Akira, Xiong Liming
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Eigenvalues and forbidden subgraphs I
Linear Algebra and its Applications, 2006 Some calculation errors in the first version are ...
Vladimir Nikiforov
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Forbidden Induced Subgraphs [PDF]
Electronic Notes in Discrete Mathematics, 2017 In descending generality I survey: five partial orderings of graphs, the induced-subgraph ordering, and examples like perfect, threshold, and mock threshold graphs. The emphasis is on how the induced subgraph ordering differs from other popular orderings and leads to different basic questions.
Thomas Zasĺavsky
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Forbidden subgraphs in the norm graph
Discrete Mathematics, 2015 We show that the norm graph constructed in [J. Koll r, L. R nyai and T. Szab , Norm-graphs and bipartite Tur n numbers, Combinatorica, 16 (1996) 399--406] with $n$ vertices about $\frac{1}{2}n^{2-1/t}$ edges, which contains no copy of $K_{t,(t-1)!+1}$, does not contain a copy of $K_{t+1,(t-1)!-1}$.
Simeon Ball, Valentina Pepe
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Disjoint stars and forbidden subgraphs
Hiroshima Mathematical Journal, 2006 Let $r,k$ be integers with $r\ge 3, k\ge 2$. We prove that if $G$ is a $K_{1,r}$-free graph of order at least $(k-1)(2r-1)+1$ with $\delta(G)\ge 2$, then $G$ contains $k$ vertex-disjoint copies of $K_{1,2}$. This result is motivated by the problem of characterizing a forbidden subgraph $H$ which satisfies the statement "every $H$-free graph of ...
Shinya Fujita
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On classes of graphs determined by forbidden subgraphs [PDF]
Czechoslovak Mathematical Journal, 1983 Svatopluk Poljak, Vojtěch Rödl
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Forbidden subgraphs of coloring graphs [PDF]
Involve, a Journal of Mathematics, 2017 Given a graph G, its k-coloring graph has vertex set given by the proper k-colorings of the vertices of G with two k-colorings adjacent if and only if they differ at exactly one vertex. Beier et al. (Discrete Math. 339:8 (2016), 2100–2112) give various characterizations of coloring graphs, including finding graphs which never arise as induced subgraphs
Francisco Alvarado +3 more
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Splits with forbidden subgraphs [PDF]
Discrete Mathematics, 2022 In this note, we fix a graph $H$ and ask into how many vertices can each vertex of a clique of size $n$ can be "split" such that the resulting graph is $H$-free. Formally: A graph is an $(n,k)$-graph if its vertex sets is a pairwise disjoint union of $n$ parts of size at most $k$ each such that there is an edge between any two distinct parts. Let $$ f(
Maria Axenovich, Ryan R. Martin
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Forbidden Subgraphs of Power Graphs [PDF]
The Electronic Journal of Combinatorics, 2021 The undirected power graph (or simply power graph) of a group $G$, denoted by $P(G)$, is a graph whose vertices are the elements of the group $G$, in which two vertices $u$ and $v$ are connected by an edge between if and only if either $u=v^i$ or $v=u^j$ for some $i$, $j$.
Manna, Pallabi +2 more
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Toughness, Forbidden Subgraphs and Pancyclicity [PDF]
Graphs and Combinatorics, 2021 AbstractMotivated by several conjectures due to Nikoghosyan, in a recent article due to Li et al., the aim was to characterize all possible graphs H such that every 1-tough H-free graph is hamiltonian. The almost complete answer was given there by the conclusion that every proper induced subgraph H of $$K_1\cup P_4$$
Wei Zheng +4 more
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