Generalized power domination of graphs

In this paper, we introduce the concept of kk-power domination which is a common generalization of domination and power domination. We extend several known results for power domination to kk-power domination. Concerning the complexity of the kk-power domination problem, we first show that deciding whether a graph admits a kk-power dominating set of size at most tt is NP-complete for chordal graphs and for bipartite graphs. We then give a linear algorithm for the problem on trees. Finally, we propose sharp upper bounds for the power domination number of connected graphs and of connected claw-free (k+2)(k+2)-regular graphs.