Results 41 to 50 of about 413 (64)

The Hamiltonian index of a graph and its branch-bonds [PDF]

open access: yes, 2001
Let $G$ be an undirected and loopless finite graph that is not a path. The minimum $m$ such that the iterated line graph $L^m(G)$ is hamiltonian is called the hamiltonian index of $G,$ denoted by $h(G).$ A reduction method to determine the hamiltonian ...
Broersma, Haitze J.   +4 more
core   +1 more source

Spectral Radius and Hamiltonicity of Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2019
In this paper, we study the Hamiltonicity of graphs with large minimum degree. Firstly, we present some conditions for a simple graph to be Hamilton-connected and traceable from every vertex in terms of the spectral radius of the graph or its complement,
Yu Guidong   +3 more
doaj   +1 more source

Directed path graphs [PDF]

open access: yes, 1996
The concept of a line digraph is generalized to that of a directed path graph. The directed path graph $\overrightarrow P_k(D)$ of a digraph D is obtained by representing the directed paths on k vertices of D by vertices.
Broersma, Hajo, Li, Xueliang
core   +1 more source

Forbidden Pairs and (k,m)-Pancyclicity

open access: yesDiscussiones Mathematicae Graph Theory, 2017
A graph G on n vertices is said to be (k, m)-pancyclic if every set of k vertices in G is contained in a cycle of length r for each r ∈ {m, m+1, . . . , n}.
Crane Charles Brian
doaj   +1 more source

CoEulerian graphs

open access: yes, 2015
We suggest a measure of "Eulerianness" of a finite directed graph and define a class of "coEulerian" graphs. These are the graphs whose Laplacian lattice is as large as possible.
Farrell, Matthew, Levine, Lionel
core   +1 more source

Dirac type condition and Hamiltonian graphs [PDF]

open access: yes, 2011
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.
Zhao, Kewen
core  

Spectral radius and traceability of connected claw-free graphs

open access: yes, 2015
Let $G$ be a connected claw-free graph on $n$ vertices and $\overline{G}$ be its complement graph. Let $\mu(G)$ be the spectral radius of $G$. Denote by $N_{n-3,3}$ the graph consisting of $K_{n-3}$ and three disjoint pendent edges. In this note we prove
Li, Binlong, Ning, Bo
core   +1 more source

On factors of 4-connected claw-free graphs [PDF]

open access: yes, 1999
We consider the existence of several different kinds of factors in 4-connected claw-free graphs. This is motivated by the following two conjectures which are in fact equivalent by a recent result of the third author.
Broersma, H.J.   +2 more
core   +3 more sources

Heavy Subgraphs, Stability and Hamiltonicity

open access: yesDiscussiones Mathematicae Graph Theory, 2017
Let G be a graph. Adopting the terminology of Broersma et al. and Čada, respectively, we say that G is 2-heavy if every induced claw (K1,3) of G contains two end-vertices each one has degree at least |V (G)|/2; and G is o-heavy if every induced claw of G
Li Binlong, Ning Bo
doaj   +1 more source

Chip-firing games on Eulerian digraphs and NP-hardness of computing the rank of a divisor on a graph

open access: yes, 2015
Baker and Norine introduced a graph-theoretic analogue of the Riemann-Roch theory. A central notion in this theory is the rank of a divisor. In this paper we prove that computing the rank of a divisor on a graph is NP-hard.
Kiss, Viktor, Tóthmérész, Lilla
core   +1 more source

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