Discussiones Mathematicae Graph Theory 23(2) (2003) 207-213
DOI: https://doi.org/10.7151/dmgt.1197
HAJÓS' THEOREM FOR LIST COLORINGS OF HYPERGRAPHS1
Claude Benzaken
Université Joseph Fourier - Laboratorie Leibniz |
Sylvain Gravier
CNRS - GeoD research group, Laboratoire Leibniz |
Riste Skrekovski2
Department of Mathematics |
Abstract
A well-known theorem of Hajós claims that every graph with chromathic number greater than k can be constructed from disjoint copies of the complete graph Kk+1 by repeated application of three simple operations. This classical result has been extended in 1978 to colorings of hypergraphs by C. Benzaken and in 1996 to list-colorings of graphs by S. Gravier. In this note, we capture both variations to extend Hajós' theorem to list-colorings of hypergraphs.Keywords: list-coloring, Hajós' construction, hypergraph.
2000 Mathematics Subject Classification: 05C15, 05C99.
References
[1] | C. Benzaken, Post's closed systems and the weak chromatic number of hypergraphs, Discrete Math. 23 (1978) 77-84, doi: 10.1016/0012-365X(78)90106-1. |
[2] | C. Benzaken, Hajós' theorem for hypergraphs, Annals of Discrete Math. 17 (1983) 53-77. |
[3] | P. Erdős, A.L. Rubin, and H. Taylor, Choosability in graphs, Congr. Numer. 26 (1980) 122-157. |
[4] | S. Gravier, A Hajós-like theorem for list colorings, Discrete Math. 152 (1996) 299-302, doi: 10.1016/0012-365X(95)00350-6. |
[5] | G. Hajós, Über eine Konstruktion nicht n-färbbarer Graphen, Wiss. Z. Martin Luther Univ. Math.-Natur. Reihe 10 (1961) 116-117. |
[6] | B. Mohar, Hajós theorem for colorings of edge-weighted graphs, manuscript, 2001. |
[7] | V.G. Vizing, Colouring the vertices of a graph in prescribed colours (in Russian), Diskret. Anal. 29 (1976) 3-10. |
[8] | X. Zhu, An analogue of Hajós's theorem for the circular chromatic number, Proc. Amer. Math. Soc. 129 (2001) 2845-2852, doi: 10.1090/S0002-9939-01-05908-1. |
Received 23 October 2001
Revised 22 May 2002
Footnotes:
1This research was partially supported by the PROTEUS Project 00874RL.
2Supported in part by
the Ministry of Science and Technology of Slovenia, Research Project Z1-3129.
3Supported in part by the Ministry of Education of Czech Republic, Project
LN00A056.
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