Logged Out Log In
SIAM J. Discrete Math. 26, pp. 193-205 (13 pages)
Roman Domination on 2-Connected Graphs
A Roman dominating function of a graph $G$ is a function $f$$: V(G) \to \{0, 1, 2\}$ such that whenever $f(v)=0$, there exists a vertex $u$ adjacent to $v$ such that $f(u) = 2$. The weight of $f$ is $w(f) = \sum_{v \in V(G)} f(v)$. The Roman domination number $\gamma_R(G)$ of $G$ is the minimum weight of a Roman dominating function of $G$. Chambers, Kinnersley, Prince, and West [SIAM J. Discrete Math., 23 (2009), pp. 1575–1586] conjectured that $\gamma_R(G) \le \lceil 2n/3 \rceil$ for any $2$-connected graph $G$ of $n$ vertices. This paper gives counterexamples to the conjecture and proves that $\gamma_R(G) \le \max\{\lceil 2n/3 \rceil, 23n/34\}$ for any $2$-connected graph $G$ of $n$ vertices. We also characterize $2$-connected graphs $G$ for which $\gamma_R(G) = 23n/34$ when $23n/34 > \lceil 2n/3 \rceil$.
© 2012 Society for Industrial and Applied Mathematics
RELATED DATABASES
To view database links for this article,
you need to log in.
KEYWORDS
PUBLICATION DATA
ARTICLE DATA
History
Received August 19, 2008
Accepted December 30, 2011
Published online February 16, 2012
Accepted December 30, 2011
Published online February 16, 2012
Digital Object Identifier
For access to fully linked references, you need to log in.




ALL SIAM Content
Scitation
Google Scholar