R. Rasi, S.M. Sheikholeslami
The smallest index of trees with given maximum degree
Discussiones Mathematicae Graph Theory
Received 02.09.2016, Revised 09.01.2017, Accepted 09.01.2017, doi: 10.7151/dmgt.2019
The harmonic index of a graph G, denoted by H(G), is defined as the sum of weights 2/[d(u)+d(v)] over all edges uv of G, where d(u) denotes the degree of a vertex u. In this paper we establish a lower bound on the harmonic index of a tree T.
harmonic index, trees