R. Wu, Z. Tang and H. Deng, “A Lower Bound for the Harmonic Index of a Graph with Minimum Degree at Least Two,” Filomat, Vol. 27, No. 1, 2013, pp. 51-55.
has been cited by the following article:
TITLE: On the Harmonic Index of Triangle-Free Graphs
AUTHORS: Jianxi Liu
KEYWORDS: Harmonic Index; Minimum Degree; Triangle-Free
JOURNAL NAME: Applied Mathematics, Vol.4 No.8, August 6, 2013
ABSTRACT: The harmonic index of a graphG is defined as where d(u) denotes the degree of a vertex u in G . In this work, we give another expression for the Harmonic index. Using this expression, we give the minimum value of the harmonic index for any triangle-free graphs with order n and minimum degree δ ≥ k for k≤ n/2 and show the corresponding extremal graph is the complete graph.