The diameter of paired-domination vertex critical graphs
Czechoslovak Mathematical Journal, Tome 58 (2008) no. 4, pp. 887-897
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In this paper we continue the study of paired-domination in graphs introduced by Haynes and Slater (Networks {\it 32} (1998), 199--206). A paired-dominating set of a graph $G$ with no isolated vertex is a dominating set of vertices whose induced subgraph has a perfect matching. The paired-domination number of $G$, denoted by $\gamma _{{\rm pr}}(G)$, is the minimum cardinality of a paired-dominating set of $G$. The graph $G$ is paired-domination vertex critical if for every vertex $v$ of $G$ that is not adjacent to a vertex of degree one, $\gamma _{{\rm pr}}(G - v) \gamma _{{\rm pr}}(G)$. We characterize the connected graphs with minimum degree one that are paired-domination vertex critical and we obtain sharp bounds on their maximum diameter. We provide an example which shows that the maximum diameter of a paired-domination vertex critical graph is at least $\frac 32(\gamma _{{\rm pr}}(G) - 2)$. For $\gamma _{{\rm pr}}(G) \le 8$, we show that this lower bound is precisely the maximum diameter of a paired-domination vertex critical graph.
In this paper we continue the study of paired-domination in graphs introduced by Haynes and Slater (Networks {\it 32} (1998), 199--206). A paired-dominating set of a graph $G$ with no isolated vertex is a dominating set of vertices whose induced subgraph has a perfect matching. The paired-domination number of $G$, denoted by $\gamma _{{\rm pr}}(G)$, is the minimum cardinality of a paired-dominating set of $G$. The graph $G$ is paired-domination vertex critical if for every vertex $v$ of $G$ that is not adjacent to a vertex of degree one, $\gamma _{{\rm pr}}(G - v) \gamma _{{\rm pr}}(G)$. We characterize the connected graphs with minimum degree one that are paired-domination vertex critical and we obtain sharp bounds on their maximum diameter. We provide an example which shows that the maximum diameter of a paired-domination vertex critical graph is at least $\frac 32(\gamma _{{\rm pr}}(G) - 2)$. For $\gamma _{{\rm pr}}(G) \le 8$, we show that this lower bound is precisely the maximum diameter of a paired-domination vertex critical graph.
Classification :
05C12, 05C35, 05C69
Keywords: paired-domination; vertex critical; bounds; diameter
Keywords: paired-domination; vertex critical; bounds; diameter
@article{CMJ_2008_58_4_a1,
author = {Henning, Michael A. and Mynhardt, Christina M.},
title = {The diameter of paired-domination vertex critical graphs},
journal = {Czechoslovak Mathematical Journal},
pages = {887--897},
year = {2008},
volume = {58},
number = {4},
mrnumber = {2471154},
zbl = {1174.05093},
language = {en},
url = {http://geodesic.mathdoc.fr/item/CMJ_2008_58_4_a1/}
}
Henning, Michael A.; Mynhardt, Christina M. The diameter of paired-domination vertex critical graphs. Czechoslovak Mathematical Journal, Tome 58 (2008) no. 4, pp. 887-897. http://geodesic.mathdoc.fr/item/CMJ_2008_58_4_a1/