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Hamilton cycles in almost distance-hereditary graphs

Bing Chen, Bo Ning (2016)

Open Mathematics

Let G be a graph on n ≥ 3 vertices. A graph G is almost distance-hereditary if each connected induced subgraph H of G has the property dH(x, y) ≤ dG(x, y) + 1 for any pair of vertices x, y ∈ V(H). Adopting the terminology introduced by Broersma et al. and Čada, a graph G is called 1-heavy if at least one of the end vertices of each induced subgraph of G isomorphic to K1,3 (a claw) has degree at least n/2, and is called claw-heavy if each claw of G has a pair of end vertices with degree sum at least...

Hamilton cycles in split graphs with large minimum degree

Ngo Dac Tan, Le Xuan Hung (2004)

Discussiones Mathematicae Graph Theory

A graph G is called a split graph if the vertex-set V of G can be partitioned into two subsets V₁ and V₂ such that the subgraphs of G induced by V₁ and V₂ are empty and complete, respectively. In this paper, we characterize hamiltonian graphs in the class of split graphs with minimum degree δ at least |V₁| - 2.

Hamilton decompositions of line graphs of some bipartite graphs

David A. Pike (2005)

Discussiones Mathematicae Graph Theory

Some bipartite Hamilton decomposable graphs that are regular of degree δ ≡ 2 (mod 4) are shown to have Hamilton decomposable line graphs. One consequence is that every bipartite Hamilton decomposable graph G with connectivity κ(G) = 2 has a Hamilton decomposable line graph L(G).

Hamiltonian colorings of graphs with long cycles

Ladislav Nebeský (2003)

Mathematica Bohemica

By a hamiltonian coloring of a connected graph G of order n 1 we mean a mapping c of V ( G ) into the set of all positive integers such that | c ( x ) - c ( y ) | n - 1 - D G ( x , y ) (where D G ( x , y ) denotes the length of a longest x - y path in G ) for all distinct x , y G . In this paper we study hamiltonian colorings of non-hamiltonian connected graphs with long cycles, mainly of connected graphs of order n 5 with circumference n - 2 .

Hamiltonian connectedness and a matching in powers of connected graphs

Elena Wisztová (1995)

Mathematica Bohemica

In this paper the following results are proved: 1. Let P n be a path with n vertices, where n 5 and n 7 , 8 . Let M be a matching in P n . Then ( P n ) 4 - M is hamiltonian-connected. 2. Let G be a connected graph of order p 5 , and let M be a matching in G . Then G 5 - M is hamiltonian-connected.

Hamiltonian-colored powers of strong digraphs

Garry Johns, Ryan Jones, Kyle Kolasinski, Ping Zhang (2012)

Discussiones Mathematicae Graph Theory

For a strong oriented graph D of order n and diameter d and an integer k with 1 ≤ k ≤ d, the kth power D k of D is that digraph having vertex set V(D) with the property that (u, v) is an arc of D k if the directed distance d D ( u , v ) from u to v in D is at most k. For every strong digraph D of order n ≥ 2 and every integer k ≥ ⌈n/2⌉, the digraph D k is Hamiltonian and the lower bound ⌈n/2⌉ is sharp. The digraph D k is distance-colored if each arc (u, v) of D k is assigned the color i where i = d D ( u , v ) . The digraph D k is Hamiltonian-colored...

Hamiltonicity in multitriangular graphs

Peter J. Owens, Hansjoachim Walther (1995)

Discussiones Mathematicae Graph Theory

The family of 5-valent polyhedral graphs whose faces are all triangles or 3s-gons, s ≥ 9, is shown to contain non-hamiltonian graphs and to have a shortness exponent smaller than one.

Hamiltonicity in Partly claw-free graphs

Moncef Abbas, Zineb Benmeziane (2009)

RAIRO - Operations Research


Matthews and Sumner have proved in [10] that if G is a 2-connected claw-free graph of order n such that δ(G) ≥ (n-2)/3, then G is Hamiltonian. We say that a graph is almost claw-free if for every vertex v of G, 〈N(v)〉 is 2-dominated and the set A of centers of claws of G is an independent set. Broersma et al. [5] have proved that if G is a 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 results by considering the graphs...

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