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arXiv · 1204.1438

On the Roman bondage number of a graph

A. Bahremandpour·Fu-Tao Hu·S. M. Sheikholeslami·Jun-Ming Xu
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Abstract

A Roman dominating function on a graph $G=(V,E)$ is a function $f:V\rightarrow\{0,1,2\}$ such that every vertex $v\in V$ with $f(v)=0$ has at least one neighbor $u\in V$ with $f(u)=2$. The weight of a Roman dominating function is the value $f(V(G))=\sum_{u\in V(G)}f(u)$. The minimum weight of a Roman dominating function on a graph $G$ is called the Roman domination number, denoted by $\gamma_{R}(G)$. The Roman bondage number $b_{R}(G)$ of a graph $G$ with maximum degree at least two is the minimum cardinality of all sets $E'\subseteq E(G)$ for which $\gamma_{R}(G-E')>\gamma_R(G)$. In this paper, we first show that the decision problem for determining $b_{\rm R}(G)$ is NP-hard even for bipartite graphs and then we establish some sharp bounds for $b_{\rm R}(G)$ and characterizes all graphs attaining some of these bounds.

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A. Bahremandpour, Fu-Tao Hu, S. M. Sheikholeslami, Jun-Ming Xu. 2012-04-06. On the Roman bondage number of a graph. https://arxiv.org/abs/1204.1438

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