Downhill domination in graphs
نویسندگان
چکیده
A path π = (v1, v2, . . . , vk+1) in a graph G = (V,E) is a downhill path if for every i, 1 ≤ i ≤ k, deg(vi) ≥ deg(vi+1), where deg(vi) denotes the degree of vertex vi ∈ V. The downhill domination number equals the minimum cardinality of a set S ⊆ V having the property that every vertex v ∈ V lies on a downhill path originating from some vertex in S. We investigate downhill domination numbers of graphs and give upper bounds. In particular, we show that the downhill domination number of a graph is at most half its order, and that the downhill domination number of a tree is at most one third its order. We characterize the graphs obtaining each of these bounds. Professor Emeritus. Work completed while attending East Tennessee State University.
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ورودعنوان ژورنال:
- Discussiones Mathematicae Graph Theory
دوره 34 شماره
صفحات -
تاریخ انتشار 2014