Extremal problems for forbidden pairs that imply hamiltonicity

• Volume: 19, Issue: 1, page 13-29
• ISSN: 2083-5892

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Abstract

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Let C denote the claw ${K}_{1,3}$, N the net (a graph obtained from a K₃ by attaching a disjoint edge to each vertex of the K₃), W the wounded (a graph obtained from a K₃ by attaching an edge to one vertex and a disjoint path P₃ to a second vertex), and ${Z}_{i}$ the graph consisting of a K₃ with a path of length i attached to one vertex. For k a fixed positive integer and n a sufficiently large integer, the minimal number of edges and the smallest clique in a k-connected graph G of order n that is CY-free (does not contain an induced copy of C or of Y) will be determined for Y a connected subgraph of either P₆, N, W, or Z₃. It should be noted that the pairs of graphs CY are precisely those forbidden pairs that imply that any 2-connected graph of order at least 10 is hamiltonian. These extremal numbers give one measure of the relative strengths of the forbidden subgraph conditions that imply a graph is hamiltonian.

How to cite

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Ralph Faudree, and András Gyárfás. "Extremal problems for forbidden pairs that imply hamiltonicity." Discussiones Mathematicae Graph Theory 19.1 (1999): 13-29. <http://eudml.org/doc/270578>.

@article{RalphFaudree1999,
abstract = {Let C denote the claw $K_\{1,3\}$, N the net (a graph obtained from a K₃ by attaching a disjoint edge to each vertex of the K₃), W the wounded (a graph obtained from a K₃ by attaching an edge to one vertex and a disjoint path P₃ to a second vertex), and $Z_i$ the graph consisting of a K₃ with a path of length i attached to one vertex. For k a fixed positive integer and n a sufficiently large integer, the minimal number of edges and the smallest clique in a k-connected graph G of order n that is CY-free (does not contain an induced copy of C or of Y) will be determined for Y a connected subgraph of either P₆, N, W, or Z₃. It should be noted that the pairs of graphs CY are precisely those forbidden pairs that imply that any 2-connected graph of order at least 10 is hamiltonian. These extremal numbers give one measure of the relative strengths of the forbidden subgraph conditions that imply a graph is hamiltonian.},
author = {Ralph Faudree, András Gyárfás},
journal = {Discussiones Mathematicae Graph Theory},
keywords = {hamiltonian; extremal numbers; forbidden subgraph; dense graphs; sparse graphs},
language = {eng},
number = {1},
pages = {13-29},
title = {Extremal problems for forbidden pairs that imply hamiltonicity},
url = {http://eudml.org/doc/270578},
volume = {19},
year = {1999},
}

TY - JOUR
AU - Ralph Faudree
AU - András Gyárfás
TI - Extremal problems for forbidden pairs that imply hamiltonicity
JO - Discussiones Mathematicae Graph Theory
PY - 1999
VL - 19
IS - 1
SP - 13
EP - 29
AB - Let C denote the claw $K_{1,3}$, N the net (a graph obtained from a K₃ by attaching a disjoint edge to each vertex of the K₃), W the wounded (a graph obtained from a K₃ by attaching an edge to one vertex and a disjoint path P₃ to a second vertex), and $Z_i$ the graph consisting of a K₃ with a path of length i attached to one vertex. For k a fixed positive integer and n a sufficiently large integer, the minimal number of edges and the smallest clique in a k-connected graph G of order n that is CY-free (does not contain an induced copy of C or of Y) will be determined for Y a connected subgraph of either P₆, N, W, or Z₃. It should be noted that the pairs of graphs CY are precisely those forbidden pairs that imply that any 2-connected graph of order at least 10 is hamiltonian. These extremal numbers give one measure of the relative strengths of the forbidden subgraph conditions that imply a graph is hamiltonian.
LA - eng
KW - hamiltonian; extremal numbers; forbidden subgraph; dense graphs; sparse graphs
UR - http://eudml.org/doc/270578
ER -

References

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6. [6] R.J. Faudree, Forbidden Subgraphs and Hamiltonian Properties - A Survey, Congressus Numerantium 116 (1996) 33-52. Zbl0895.05037
7. [7] R.J. Faudree, E. Flandrin and Z. Ryjácek, Claw-free Graphs - A Survey, Discrete Math. 164 (1997) 87-147, doi: 10.1016/S0012-365X(96)00045-3. Zbl0879.05043
8. [8] R.J. Faudree and R.J. Gould, Characterizing Forbidden Pairs for Hamiltonian Properties, Discrete Math. 173 (1977) 45-60, doi: 10.1016/S0012-365X(96)00147-1. Zbl0879.05050
9. [9] J.K. Kim, The Ramsey number R(3,t) has order of magnitude t²/logt, Random Structures Algorithms 7 (1995) 173-207, doi: 10.1002/rsa.3240070302. Zbl0832.05084
10. [10] O. Ore, Note on Hamiltonian Circuits, Amer. Math. Monthly 67 (1960) 55, doi: 10.2307/2308928.

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