Simultaneous Domination in Graphs
arXiv:1301.4008
Abstract
Let be graphs with the same vertex set . A subset is a simultaneous dominating set if for every , , every vertex of not in is adjacent to a vertex in in ; that is, the set is simultaneously a dominating set in each graph . The cardinality of a smallest such set is the simultaneous domination number. We present general upper bounds on the simultaneous domination number. We investigate bounds in special cases, including the cases when the factors, , are -regular or the disjoint union of copies of . Further we study the case when each factor is a cycle.