Results 1 to 10 of about 9,740 (155)

Forbidden Subgraphs for Existences of (Connected) 2-Factors of a Graph

open access: yesDiscussiones Mathematicae Graph Theory, 2023
Clearly, having a 2-factor in a graph is a necessary condition for a graph to be hamiltonian, while having an even factor in graph is a necessary condition for a graph to have a 2-factor.
Yang Xiaojing, Xiong Liming
doaj   +1 more source

Forbidden Subgraphs for Collapsible Graphs and Supereulerian Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2022
In this paper, we completely characterize the connected forbidden subgraphs and pairs of connected forbidden subgraphs that force a 2-edge-connected (2-connected) graph to be collapsible.
Liu Xia, Xiong Liming
doaj   +1 more source

Hamiltonian Extendable Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2022
A graph is called Hamiltonian extendable if there exists a Hamiltonian path between any two nonadjacent vertices. In this paper, we give an explicit formula of the minimum number of edges for Hamiltonian extendable graphs and we also characterize the ...
Yang Xiaojing, Xiong Liming
doaj   +1 more source

Tree in forbidden triples generating a finite set of graphs with high connectivity

open access: yesAKCE International Journal of Graphs and Combinatorics, 2020
For a graph and a set of connected graphs, is said be -free if does not contain any member of as an induced subgraph. For , we let denote the set of all -connected -free graphs.
Yoshimi Egawa, Zhixian Zhao
doaj   +1 more source

Paw-Type Characterization of Hourglass-Free Hamilton-Connected Graphs

open access: yesAxioms, 2023
This paper introduces the forbidden subgraph conditions for Hamilton-connected graphs. If the degree sequence of the graph is (4,2,2,2,2) and it is connected, then it is called hourglassΓ0.
Panpan Wang, Liming Xiong
doaj   +1 more source

Characterizing Forbidden Pairs for the Edge-Connectivity of a Connected Graph to Be Its Minimum Degree

open access: yesAxioms, 2022
Let H be a class of given graphs. A graph G is said to be H-free if G contains no induced copies of H for any H∈H. In this article, we characterize all connected subgraph pairs {R,S} guranteeing the edge-connectivity of a connected {R,S}-free graph to ...
Junfeng Du, Ziwen Huang, Liming Xiong
doaj   +1 more source

The Price of Connectivity for Vertex Cover [PDF]

open access: yes, 2013
The vertex cover number of a graph is the minimum number of vertices that are needed to cover all edges. When those vertices are further required to induce a connected subgraph, the corresponding number is called the connected vertex cover number, and is
Camby, Eglantine   +3 more
core   +4 more sources

Classes of graphs with restricted interval models [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 1999
We introduce q-proper interval graphs as interval graphs with interval models in which no interval is properly contained in more than q other intervals, and also provide a forbidden induced subgraph characterization of this class of graphs. We initiate a
Andrzej Proskurowski, Jan Arne Telle
doaj   +3 more sources

Quantum query complexity of minor-closed graph properties [PDF]

open access: yes, 2011
We study the quantum query complexity of minor-closed graph properties, which include such problems as determining whether an $n$-vertex graph is planar, is a forest, or does not contain a path of a given length. We show that most minor-closed properties-
Childs, Andrew M., Kothari, Robin
core   +5 more sources

Forbidden subgraph pairs for traceability of block-chains

open access: yesElectronic Journal of Graph Theory and Applications, 2013
A block-chain is a graph whose block graph is a path, i.e. it is either a $P_1$, a $P_2$, or a 2-connected graph, or a graph of connectivity 1 with exactly two end-blocks. A graph is called traceable if it contains a Hamilton path.
Binlong Li   +2 more
doaj   +1 more source

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