An improvement on Vizing's conjecture

نویسنده

  • Yunjian Wu
چکیده

Let γ(G) denote the domination number of a graph G. A Roman domination function of a graph G is a function f : V → {0, 1, 2} such that every vertex with 0 has a neighbor with 2. The Roman domination number γR(G) is the minimum of f(V (G)) = Σv∈V f(v) over all such functions. Let G H denote the Cartesian product of graphs G and H. We prove that γ(G)γ(H) ≤ γR(G H) for all simple graphs G and H, which is an improvement of γ(G)γ(H) ≤ 2γ(G H) given by Clark and Suen [1], since γ(G H) ≤ γR(G H) ≤ 2γ(G H).

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عنوان ژورنال:
  • Inf. Process. Lett.

دوره 113  شماره 

صفحات  -

تاریخ انتشار 2013