In a graph G, a set X is called a stable set if any two vertices of X are nonadjacent. A set X is called a dominating set if every vertex of V-X is joined to at least one vertex of X. A set Xis called an irredundant set if every vertex of X, not isolated in X, has at least one proper neighbor, that
Domination and irredundance in the queens' graph
โ Scribed by A.P Burger; E.J Cockayne; C.M Mynhardt
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 1020 KB
- Volume
- 163
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
The vertices of the queem;' graph {~, are the squares of an n ร n chessboard and two squares are adjacent ifa queen placed on one covers the other. It is shown that the domination num;~'r of Q. is at most 31n/54 + O(1), that Q. possesses minimal dominating sets of cardina~tty 5n/2 -O(l) and that the cardinality of any irredundant set of vertices of Q, (n/> 9) is at most L6n +6-8x/n + ~ +1].
๐ SIMILAR VOLUMES
## Abstract A vertex __x__ in a subset __X__ of vertices of an undericted graph is __redundant__ if its closed neighbourhood is contained in the union of closed neighborhoods of vertices of __X__ โ {__x__}. In the context of a communications network, this means that any vertex that may receive comm
In this paper we consider the following parameters: IR(G), the upper irredundance number, which is the order of the largest maximal irredundant set, I'(G), the upper domination number, which is the order of the largest minimal dominating set and /3(G), the independence number, which is the order of
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
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