1,877 research outputs found

    Domination number of graphs with minimum degree five

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    We prove that for every graph GG on nn vertices and with minimum degree five, the domination number γ(G)\gamma(G) cannot exceed n/3n/3. The proof combines an algorithmic approach and the discharging method. Using the same technique, we provide a shorter proof for the known upper bound 4n/114n/11 on the domination number of graphs of minimum degree four.Comment: 17 page

    Power domination in maximal planar graphs

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    Power domination in graphs emerged from the problem of monitoring an electrical system by placing as few measurement devices in the system as possible. It corresponds to a variant of domination that includes the possibility of propagation. For measurement devices placed on a set S of vertices of a graph G, the set of monitored vertices is initially the set S together with all its neighbors. Then iteratively, whenever some monitored vertex v has a single neighbor u not yet monitored, u gets monitored. A set S is said to be a power dominating set of the graph G if all vertices of G eventually are monitored. The power domination number of a graph is the minimum size of a power dominating set. In this paper, we prove that any maximal planar graph of order n \ge 6 admits a power dominating set of size at most (n--2)/4

    Independent Domination in Some Wheel Related Graphs

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    A set S of vertices in a graph G is called an independent dominating set if S is both independent and dominating. The independent domination number of G is the minimum cardinality of an independent dominating set in G . In this paper, we investigate the exact value of independent domination number for some wheel related graphs
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