Improvement of some bounds for the Randić Estrada index of graphs
Authors: Akbar Jahanbani, Hajar Shooshtari, Izudin Redžepović
Keywords: Randić eigenvalues of a graph, Estrada index, Randić Estrada index, bounds, graph invariants
Abstract:
Let G be a graph with n vertices and m edges, and let ρ1,ρ2, . . . ,ρn be the eigenvalues of the Randić matrix. The Randić Estrada index of G is REE(G) = Σni =1 eρi . In this paper, we establish bounds for the Randić Estrada index in terms of graph invariants such as the number of vertices and some Randić eigenvalues of graphs and improve some previously published lower bounds.