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Article Dans Une Revue Discrete Mathematics Année : 2006

On the oriented chromatic number of graphs with given excess

Mohammad Hosseini Dolama
  • Fonction : Auteur

Résumé

The excess of a graph G is defined as the minimum number of edges that must be deleted from G in order to get a forest. We prove that every graph with excess at most k has chromatic number at most \frac{1}{2}(3+\sqrt{1+8k}) and that this bound is tight. Moreover, we prove that the oriented chromatic number of any graph with excess k is at most k+3, except for graphs having excess 1 and containing a directed cycle on 5 vertices which have oriented chromatic number 5. This bound is tight for k\le 4.
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Dates et versions

hal-00307541 , version 1 (29-07-2008)

Identifiants

  • HAL Id : hal-00307541 , version 1

Citer

Mohammad Hosseini Dolama, Eric Sopena. On the oriented chromatic number of graphs with given excess. Discrete Mathematics, 2006, 306, pp.1342--1350. ⟨hal-00307541⟩

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