On edge-edge domination in graphs

Abstract

In this paper we further study the concept of edge-edge domination in graphs. We observe that the edge-edge domination number of a graph may increase or decrease or remains same when a edge is removed from a graph. We proved a necessary and sufficient condition under which the edge-edge domination number of a graph increases and also we proved a necessary and sufficient condition under which the edge-edge domination number of a graph decreases. For this purpose we introduce two new concepts namely e-dominating neighbourhood of an edge and private edge-edge neighbourhood of an edge with respect to a set containing the edge. Some examples also have been given.