On Harary Spectral Radius with Given Parameters

Zhongxun Zhu1, Hongyun Wei1, Xiaojun Ma1, Tengjiao Wang1, Wenjing Zhu1
1College of Mathematics and Statistics, South Central University for Nationalities, Wuhan 430074, P.R. China

Abstract

The Harary spectral radius \(\rho(G)\) of a graph \(G\) is the largest eigenvalue of the Harary matrix \(RD(G)\). In this paper, we determine graphs with the largest Harary spectral radius in four classes of simple connected graphs with \(n\) vertices: with given matching number, vertex connectivity, edge connectivity, and chromatic number, respectively.