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Hamiltonicity in Partly claw-free graphs

Published online by Cambridge University Press:  28 January 2009

Moncef Abbas
Affiliation:
Université des Sciences et de la Technologie Houari Boumedienne Faculté de Mathématiques, BP 32, El Alia Alger 16111, Algérie; [email protected]
Zineb Benmeziane
Affiliation:
Université des Sciences et de la Technologie Houari Boumedienne Faculté de Mathématiques, BP 32, El Alia Alger 16111, Algérie; [email protected]
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Abstract


Matthews and Sumner have proved in [10] that if G is a 2-connectedclaw-free graph of order n such that δ(G) ≥ (n-2)/3, then G isHamiltonian. We say that a graph is almost claw-free if for every vertexv of G, 〈N(v)〉 is 2-dominated and the set A of centers of claws of G isan independent set. Broersma et al. [5] have proved that if G isa 2-connected almost claw-free graph of order n such that n such that δ(G) ≥ (n-2)/3, then G is Hamiltonian. We generalize these resultsby considering the graphs satisfying the following property: for everyvertex v ∈ A, there exist exactly two vertices x and y of V\A such that N(v) ⊆ N[x] N[y]. We extend some other knownresults on claw-free graphs to this new class of graphs.

Type
Research Article
Copyright
© EDP Sciences, ROADEF, SMAI, 2009

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