Bounds On The Disjunctive Total Domination Number Of A Tree
Let G be a graph with no isolated vertex. In this paper, we study a parameter that is a relaxation of arguably the most important domination parameter, namely the total domination number, γt(G). A set S of vertices in G is a disjunctive total dominating set of G if every vertex is adjacent to a vertex of S or has at least two vertices in S at distance 2 from it. The disjunctive total domination number, [...] γtd(G) , is the minimum cardinality of such a set. We observe that [...] γtd(G)≤γt(G)...