On well-edge-dominated graphs

Abstract

A graph is said to be well-edge-dominated if all its minimal edge dominating sets are minimum. It is known that every well-edge-dominated graph $G$ is also equimatchable, meaning that every maximal matching in $G$ is maximum. In this paper, we show that if $G$ is a connected, triangle-free, nonbipartite, well-edge-dominated graph, then $G$ is one of three graphs. We also characterize the well-edge-dominated split graphs and Cartesian products. In particular, we show that a connected Cartesian product $G\square H$ is well-edge-dominated, where $G$ and $H$ have order at least $2$, if and only if $G\square H=K_2\square K_2$.

18 pages, 2 figures, 18 references