Domination by Union of Complete Graphs

Let G be a graph with domination number γ(G). A dominating set S ⊆ V (G) has property UK if all components of the subgraph it induces in G are complete. The union of complete graphs domination number of a graph G, denoted γuk(G), is the minimum possible size of a dominating set of G, which has property UK. Results on changing and unchanging of γuk after vertex removal are presented. Also forbidden subgraph conditions sufficient to imply γ(G) = γuk(G) are given.