Signed total domination number of a graph
Czechoslovak Mathematical Journal, Tome 51 (2001) no. 2, pp. 225-229
Cet article a éte moissonné depuis la source Czech Digital Mathematics Library
The signed total domination number of a graph is a certain variant of the domination number. If $v$ is a vertex of a graph $G$, then $N(v)$ is its oper neighbourhood, i.e. the set of all vertices adjacent to $v$ in $G$. A mapping $f: V(G) \rightarrow \lbrace -1, 1\rbrace $, where $V(G)$ is the vertex set of $G$, is called a signed total dominating function (STDF) on $G$, if $\sum _{x \in N(v)} f(x) \ge 1$ for each $v \in V(G)$. The minimum of values $\sum _{x \in V(G)} f(x)$, taken over all STDF’s of $G$, is called the signed total domination number of $G$ and denoted by $\gamma _{\mathrm st}(G)$. A theorem stating lower bounds for $\gamma _{\mathrm st}(G)$ is stated for the case of regular graphs. The values of this number are found for complete graphs, circuits, complete bipartite graphs and graphs on $n$-side prisms. At the end it is proved that $\gamma _{\mathrm st}(G)$ is not bounded from below in general.
The signed total domination number of a graph is a certain variant of the domination number. If $v$ is a vertex of a graph $G$, then $N(v)$ is its oper neighbourhood, i.e. the set of all vertices adjacent to $v$ in $G$. A mapping $f: V(G) \rightarrow \lbrace -1, 1\rbrace $, where $V(G)$ is the vertex set of $G$, is called a signed total dominating function (STDF) on $G$, if $\sum _{x \in N(v)} f(x) \ge 1$ for each $v \in V(G)$. The minimum of values $\sum _{x \in V(G)} f(x)$, taken over all STDF’s of $G$, is called the signed total domination number of $G$ and denoted by $\gamma _{\mathrm st}(G)$. A theorem stating lower bounds for $\gamma _{\mathrm st}(G)$ is stated for the case of regular graphs. The values of this number are found for complete graphs, circuits, complete bipartite graphs and graphs on $n$-side prisms. At the end it is proved that $\gamma _{\mathrm st}(G)$ is not bounded from below in general.
Classification :
05C35, 05C69
Keywords: signed total dominating function; signed total domination number; regular graph; circuit; complete graph; complete bipartite graph; Cartesian product of graphs
Keywords: signed total dominating function; signed total domination number; regular graph; circuit; complete graph; complete bipartite graph; Cartesian product of graphs
@article{CMJ_2001_51_2_a0,
author = {Zelinka, Bohdan},
title = {Signed total domination number of a graph},
journal = {Czechoslovak Mathematical Journal},
pages = {225--229},
year = {2001},
volume = {51},
number = {2},
mrnumber = {1844306},
zbl = {0977.05096},
language = {en},
url = {http://geodesic.mathdoc.fr/item/CMJ_2001_51_2_a0/}
}
Zelinka, Bohdan. Signed total domination number of a graph. Czechoslovak Mathematical Journal, Tome 51 (2001) no. 2, pp. 225-229. http://geodesic.mathdoc.fr/item/CMJ_2001_51_2_a0/
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