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Minors in Graphs with High Chromatic Number

Published online by Cambridge University Press:  13 April 2011

THOMAS BÖHME
Affiliation:
Institut für Mathematik, Technische Universität Ilmenau, Ilmenau, Germany (e-mail: [email protected])
ALEXANDR KOSTOCHKA
Affiliation:
Department of Mathematics, University of Illinois, Urbana, IL 61801, USA and Sobolev Institute of Mathematics, Novosibirsk, Russia (e-mail: [email protected])
ANDREW THOMASON
Affiliation:
DPMMS, Centre for Mathematical Sciences, Wilberforce Road, Cambridge, UK (e-mail: [email protected])

Abstract

We develop lower bounds on the Hadwiger number h(G) of graphs G with high chromatic number. In particular, if G has n vertices and chromatic number k then h(G) ≥ (4kn)/3.

Type
Paper
Copyright
Copyright © Cambridge University Press 2011

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References

[1]Dirac, G. A. (1964) Homomorphism theorems for graphs. Math. Ann. 153 6980.CrossRefGoogle Scholar
[2]Duchet, P. and Meyniel, H. (1982) On Hadwiger's number and the stability number. In Graph Theory (Bollobás, B., ed.), Vol. 13 of Annals of Discrete Mathematics, North-Holland, pp. 7173.Google Scholar
[3]Gallai, T. (1963) Kritische Graphen II. Publ. Math. Inst. Hungar. Acad. Sci. 8 373395.Google Scholar
[4]Kawarabayashi, K. and Song, Z. (2007) Independence numbers and clique minors. J. Graph Theory 56 219226.CrossRefGoogle Scholar
[5]Plummer, M. D., Stiebitz, M. and Toft, B. (2003) On a special case of Hadwiger's conjecture. Discussiones Mathematicae Graph Theory 23 333363.CrossRefGoogle Scholar
[6]Robertson, N., Seymour, P. D. and Thomas, R. (1993) Hadwiger's conjecture for K 6-free graphs. Combinatorica 13 279362.CrossRefGoogle Scholar
[7]Stehlík, M. (2009) Critical graphs with connected complements. J. Combin. Theory Ser. B 89 189194.CrossRefGoogle Scholar
[8]Wagner, K. (1937) Über eine Eigenschaft der ebenen Komplexe. Math. Ann. 114 570590.CrossRefGoogle Scholar