2012/11/25 by You Lu, Lu, You, Jun-Ming Xu +1
Mathematics · #05C69 #Combinatorics (math.CO) #FOS: Mathematics #math.CO #msc:05C69
paper · pdf · doi:10.48550/arxiv.1211.5742
arxiv created 2012/11/25 · arxiv updated 2012/11/27
Let G=(V,E) be a graph and p a positive integer. The p-domination number \gp(G) is the minimum cardinality of a set D⊆ V with |NG(x)∩ D|≥ p for all x∈ V∖ D. The p-reinforcement number rp(G) is the smallest number of edges whose addition to G results in a graph G' with \gp(G')<\gp(G). Recently, it was proved by Lu et al. that rp(T)≤ p+1 for a tree T and p≥ 2. In this paper, we characterize all trees attaining this upper bound for p≥ 3.