Improved McClelland and Koolen–Moulton bounds for distance energy of a graph

Abstract

Abstract Let G be a graph with n vertices and m edges. The term energy of a graph G was introduced by I. Gutman in chemistry due to its relevance to the total π-electron energy of a carbon compound. An analogous energy ED(G) $\mathcal{E}_{D}(G)$, called the distance energy, was defined by Indulal et al. (MATCH Commun. Math. Comput. Chem. 60:461–472, 2008) in 2008. McClelland and Koolen–Moulton bounds for distance energy were established subsequently by Ramane et al. (Kragujev. J. Math. 31:59–68, 2008). The lower and upper bounds for ED(G) $\mathcal{E}_{D}(G)$ obtained in this paper are better than the McClelland and Koolen–Moulton bounds.

Keywords

• Distance matrix
• Distance spectrum
• Bounds for distance energy of graph