On minimum intersections of certain secondary dominating sets in graphs

Abstract

In this paper we consider secondary dominating sets, also named as \((1,k)\)-dominating sets, introduced by Hedetniemi et al. in 2008. In particular, we study intersections of the \((1,1)\)-dominating sets and proper \((1,2)\)-dominating sets. We introduce \((1,\overline{2})\)-intersection index as the minimum possible cardinality of such intersection and determine its value for some classes of graphs.