On the Lower Bounds of Signed Edge Domination Numbers in Graphs

Let r′s(G) denote the signed edge domination number of a graph G. In this paper, we prove that γ′s(G)≥「4δ-n~28」 for any graph G of order n, and discuss the signed edge domination numbers for trees and complete bipartite graphs, and pose the corresponding several problems and conjectures.