An improved upper bound on the domination number of a tree (Q6180641)

A dominating set in a graph is a subset of vertices such that every vertex in the graph is either in the dominating set or adjacent to a vertex in the dominating set. The domination number of a graph is the minimum cardinality among all dominating sets of the graph. The author improves the previously known upper bound on the domination number of trees by giving the tight bound in terms of the order of a graph, its number of support vertices, strong support vertices, support link vertices, and strong leaves.