%0 Journal Article %T Neighbourhood total domination in graphs %A S. Arumugam %A C. Sivagnanam %J Opuscula Mathematica %D 2011 %I AGH University of Science and Technology %X Let G = (V;E) be a graph without isolated vertices. A dominating set S of G is called a neighbourhood total dominating set (ntd-set) if the induced subgraph has no isolated vertices. The minimum cardinality of a ntd-set of G is called the neighbourhood total domination number of G and is denoted by $gamma _{nt}(G)$. The maximum order of a partition of V into ntd-sets is called the neighbourhood total domatic number of G and is denoted by $d_{nt}(G)$. In this paper we initiate a study of these parameters. %K neighbourhood total domination %K total domination %K connected domination %K paired domination %K neighbourhood total domatic number %U http://www.opuscula.agh.edu.pl/vol31/4/art/opuscula_math_3136.pdf