In the Square of Graphs, Hamiltonicity and Pancyclicity, Hamiltonian Connectedness and Panconnectedness Are Equivalent Concepts.
H. Fleischner (1976)
Monatshefte für Mathematik
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H. Fleischner (1976)
Monatshefte für Mathematik
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Zhao, Kewen (2011)
Serdica Mathematical Journal
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2010 Mathematics Subject Classification: 05C38, 05C45. In 1952, Dirac introduced the degree type condition and proved that if G is a connected graph of order n і 3 such that its minimum degree satisfies d(G) і n/2, then G is Hamiltonian. In this paper we investigate a further condition and prove that if G is a connected graph of order n і 3 such that d(G) і (n-2)/2, then G is Hamiltonian or G belongs to four classes of well-structured exceptional graphs.
Z. Skupień (1989)
Banach Center Publications
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Ronald J. Gould (1981)
Colloquium Mathematicae
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Kewen Zhao, Ronald J. Gould (2010)
Colloquium Mathematicae
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An independent set S of a graph G is said to be essential if S has a pair of vertices that are distance two apart in G. In 1994, Song and Zhang proved that if for each independent set S of cardinality k+1, one of the following condition holds: (i) there exist u ≠ v ∈ S such that d(u) + d(v) ≥ n or |N(u) ∩ N(v)| ≥ α (G); (ii) for any distinct u and v in S, |N(u) ∪ N(v)| ≥ n - max{d(x): x ∈ S}, then G is Hamiltonian. We prove that if for each...
Jill R. Faudree, Ralph J. Faudree, Ronald J. Gould, Michael S. Jacobson, Colton Magnant (2010)
Discussiones Mathematicae Graph Theory
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The Chvátal-Erdös theorems imply that if G is a graph of order n ≥ 3 with κ(G) ≥ α(G), then G is hamiltonian, and if κ(G) > α(G), then G is hamiltonian-connected. We generalize these results by replacing the connectivity and independence number conditions with a weaker minimum degree and independence number condition in the presence of sufficient connectivity. More specifically, it is noted that if G is a graph of order n and k ≥ 2 is a positive integer such that κ(G) ≥ k, δ(G) >...
Jens-P. Bode, Anika Fricke, Arnfried Kemnitz (2015)
Discussiones Mathematicae Graph Theory
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In 1980 Bondy [2] proved that a (k+s)-connected graph of order n ≥ 3 is traceable (s = −1) or Hamiltonian (s = 0) or Hamiltonian-connected (s = 1) if the degree sum of every set of k+1 pairwise nonadjacent vertices is at least ((k+1)(n+s−1)+1)/2. It is shown in [1] that one can allow exceptional (k+ 1)-sets violating this condition and still implying the considered Hamiltonian property. In this note we generalize this result for s = −1 and s = 0 and graphs that fulfill a certain connectivity...
Tudor Zamfirescu (1971)
Rendiconti del Seminario Matematico della Università di Padova
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Gary Chartrand, S. F. Kapoor (1974)
Colloquium Mathematicae
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Ján Ninčák (1974)
Commentationes Mathematicae Universitatis Carolinae
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Hüseyin Kocak (1984)
Monatshefte für Mathematik
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Erhard Hexel (2017)
Discussiones Mathematicae Graph Theory
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The H-force number h(G) of a hamiltonian graph G is the smallest cardinality of a set A ⊆ V (G) such that each cycle containing all vertices of A is hamiltonian. In this paper a lower and an upper bound of h(G) is given. Such graphs, for which h(G) assumes the lower bound are characterized by a cycle extendability property. The H-force number of hamiltonian graphs which are exactly 2-connected can be calculated by a decomposition formula.
Demovič, A. (1995)
Acta Mathematica Universitatis Comenianae. New Series
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