We introduce in this paper the notion of the chromatic number of an oriented graph G (that is of an antisymmetric directed graph) defined as the minimum order of an oriented graph H such that G admits a homomorphism to H. We study the chromatic number of oriented k-trees and of oriented graphs with
The chromatic numbers of random hypergraphs
β Scribed by Michael Krivelevich; Benny Sudakov
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 261 KB
- Volume
- 12
- Category
- Article
- ISSN
- 1042-9832
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β¦ Synopsis
For a pair of integers 1 F β₯r, the β₯-chromatic number of an r-uniform Ε½ . hypergraph H s V, E is the minimal k, for which there exists a partition of V into subsets < < T, . . . , T such that e l T F β₯ for every e g E. In this paper we determine the asymptotic 1 k i Ε½ . behavior of the β₯-chromatic number of the random r-uniform hypergraph H n, p for all r Ε½ yrq1 . possible values of β₯ and for all values of p down to p s β° n .
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