Institution: | a Institute for Studies in Theoretical Physics and Mathematics, P.O. Box 19395-5746, Tehran, Iran b Department of Mathematical Sciences, Sharif University of Technology, P.O. Box 11365-9415, Tehran, Iran c Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran |
Abstract: | Let be the signed edge domination number of G. In 2006, Xu conjectured that: for any 2-connected graph G of order n(n≥2), . In this article we show that this conjecture is not true. More precisely, we show that for any positive integer m, there exists an m-connected graph G such that . Also for every two natural numbers m and n, we determine , where Km,n is the complete bipartite graph with part sizes m and n. |