Domination numbers in graphs with removed edge or set of edges
It is known that the removal of an edge from a graph G cannot decrease a domination number γ(G) and can increase it by at most one. Thus we can write that γ(G) ≤ γ(G-e) ≤ γ(G)+1 when an arbitrary edge e is removed. Here we present similar inequalities for the weakly connected domination number and the connected domination number , i.e., we show that and if G and G-e are connected. Additionally we show that and if G and G - Eₚ are connected and Eₚ = E(Hₚ) where Hₚ of order p is a connected...