Global Hop Domination Numbers of Graphs

A set S subset of V(G) is a hop dominating set of G if for each v is an element of V(G) \ S, there exists w is an element of S such that d(G) (v, w) = 2. It is a global hop dominating set of G if it is a hop dominating set of both G and the complement (G) over bar of G. The minimum cardinality of a global hop dominating set of G, denoted by gamma(gh)(G), is called the global hop domination number of G. In this paper, we study the concept of global hop domination in graphs resulting from some binary operations.