Exact algorithms for dominating induced matchings

Say that an edge of a graph G dominates itself and every other edge adjacent to it. An edge dominating set of a graph G = (V,E) is a subset of edges E′ ⊆ E which dominates all edges of G. In particular, if every edge of G is dominated by exactly one edge of E′ then E′ is a dominating induced matching. It is known that not every graph admits a dominating induced matching, while the problem to decide if it does admit is NP-complete. In this paper we consider the problem of finding a minimum weighted dominating induced matching, if any, of a graph with weighted edges. We describe two exact algorithms for general graphs. The algorithms are efficient in the cases where G admits a known vertex dominating set of small size, or when G contains a polynomial number of maximal independent sets.