## Abstract One of the basic results in graph colouring is Brooks' theorem [R. L. Brooks, Proc Cambridge Phil Soc 37 (1941) 194โ197], which asserts that the chromatic number of every connected graph, that is not a complete graph or an odd cycle, does not exceed its maximum degree. As an extension o
On the Number of Edges in Hypergraphs Critical with Respect to Strong Colourings
โ Scribed by Alexandr V. Kostochka; Douglas R. Woodall
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 94 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0195-6698
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โฆ Synopsis
A colouring of the vertices of a hypergraph G is called strong if, for every edge A, the colours of all vertices in A are distinct. It corresponds to a colouring of the generated graph (G) obtained from G by replacing every edge by a clique. We estimate the minimum number of edges possible in a k-critical t-uniform hypergraph with a given number of vertices. In particular we show that, for k โฅ t + 2, the problem reduces in a way to the corresponding problem for graphs. In the case when the generated graph of the hypergraph has bounded clique number, we give a lower bound that is valid for sufficiently large k and is asymptotically tight in k; this bound also holds for list strong colourings.
๐ SIMILAR VOLUMES
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