The sequence of upper and lower domination, independence and irredundance numbers of a graph
โ Scribed by E.J. Cockayne; C.M. Mynhardt
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 803 KB
- Volume
- 122
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
Necessary and sufficient conditions are established for the existence of a graph whose upper and lower domination, independence and irredundance numbers are six given positive integers. This result shows that the only relationships between these six parameters which hold for all graphs and which do not involve other graph theoretical parameters, are already known.
๐ SIMILAR VOLUMES
For a graph G, the definitions of doknation number, denoted y(G), and independent domination number, denoted i(G), are given, and the following results are obtained: oorollrrg 1. For any graph G, y(L(G)) = i@(G)), where Z,(G) is the line graph of G. (This $xh!s t.lic rtsult ~(L(T))~i(L(T)), h w ere
Let ฮณ(G) and ir(G) denote the domination number and the irredundance number of a graph G, respectively. Allan and Laskar [Proc. 9th Southeast Conf. on Combin., Graph Theory & Comp. (1978) 43-56] and Bollobรกs and Cock- ayne [J. Graph Theory (1979) 241-249] proved independently that ฮณ(G) < 2ir(G) for
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