Upper total domination in claw-free graphs
β Scribed by Odile Favaron; Michael A. Henning
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 114 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0364-9024
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β¦ Synopsis
Abstract
A set S of vertices in a graph G is a total dominating set of G if every vertex of G is adjacent to some vertex in S (other than itself). The maximum cardinality of a minimal total dominating set of G is the upper total domination number of G, denoted by Ξ~t~(G). We establish bounds on Ξ~t~(G) for clawβfree graphs G in terms of the number n of vertices and the minimum degree Ξ΄ of G. We show that $\Gamma _t(G) \le 2(n+1)/3$ if $\delta \in { 1,2}, \Gamma _t(G) \le 4n/(\delta + 3)$ if $\delta \in { 3,4}$, and $\Gamma _t(G) \le n/2$ if Ξ΄ββ₯β5. The extremal graphs are characterized. Β© 2003 Wiley Periodicals, Inc. J Graph Theory 44: 148β158, 2003
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