In this paper, we continue the study of neighborhood total domination in graphs first studied by Arumugam and Sivagnanam [Opuscula Math. 31 (2011), 519–531]. A neighborhood total dominating set, abbreviated NTD-set, in a graph G is a dominating set S in G with the property that the subgraph induced by the open neighborhood of the set S has no isolated vertex. The neighborhood total domination n...

For a connected graph G and any non-empty S ⊆ V (G), S is called a weakly connected dominating set of G if the subgraph obtained from G by removing all edges each joining any two vertices in V (G) \ S is connected. The weakly connected domination number γw(G) is defined to be the minimum integer k with |S| = k for some weakly connected dominating set S of G. In this note, we extend a result on ...

Let G = (V,E) be a graph. The distance between two vertices u and v in a connected graph G is the length of the shortest (u−v) path in G. A set D ⊆ V (G) is a dominating set if every vertex of G is at distance at most 1 from an element of D. The domination number of G is the minimum cardinality of a dominating set of G. A set D ⊆ V (G) is a 2-distance dominating set if every vertex of G is at d...

Let G = (V,E) be a connected graph, An equitable dominating S of a graph G is called the neighborhood connected equitable dominating set (nced-set) if the induced subgraph 〈Ne(S)〉 is connected The minimum cardinality of a nced-set of G is called the neighborhood connected equitable domination number of G and is denoted by γnce(G). In this paper we initiate a study of this parameter. For any gra...