Communications in Combinatorics and Optimization (Jan 2017)
On the signed Roman edge $k$-domination in graphs
Abstract
Let $k\geq 1$ be an integer, and $G=(V,E)$ be a finite and simple graph. The closed neighborhood $N_G[e]$ of an edge $e$ in a graph $G$ is the set consisting of $e$ and all edges having a common end-vertex with $e$. A signed Roman edge $k$-dominating function (SREkDF) on a graph $G$ is a function $f:E \rightarrow \{-1,1,2\}$ satisfying the conditions that (i) for every edge $e$ of $G$, $\sum _{x\in N[e]} f(x)\geq k$ and (ii) every edge $e$ for which $f(e)=-1$ is adjacent to at least one edge $e'$ for which $f(e')=2$. The minimum of the values $\sum_{e\in E}f(e)$, taken over all signed Roman edge $k$-dominating functions $f$ of $G$, is called the signed Roman edge $k$-domination number of $G$ and is denoted by $\gamma'_{sRk}(G)$. In this paper we establish some new bounds on the signed Roman edge $k$-domination number.
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