A Characterization of Connected (1, 2)-Domination Graphs of Tournaments
نویسندگان
چکیده
Recently, Hedetniemi et al. introduced (1, 2)-domination in graphs, and the authors extended that concept to (1, 2)-domination graphs of digraphs. Given vertices x and y in a digraph D, x and y form a (1, 2)-dominating pair if and only if for every other vertex z in D, z is one step away from x or y and at most two steps away from the other. The (1, 2)-dominating graph of D, dom1,2 (D) , is defined to be the graph G = (V, E) , where V (G) = V (D) , and xy is an edge of G whenever x and y form a (1, 2)-dominating pair in D. In this paper, we characterize all connected graphs that can be (1, 2)-dominating graphs of tournaments.
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تاریخ انتشار 2011