Indian Journal of Pure and Applied Mathematics, ( ISI ), Volume (52), No (2), Year (2021-6) , Pages (548-557)
Title : ( Distance between the spectra of certain graphs )
Authors: Mohsen Alinejad , Kazem Khashyarmanesh , Mojgan Afkhami ,Access to full-text not allowed by authors
Abstract
Richard Brualdi in [9] proposed the following problems: Problem A. Investigate cs(Gn) for special classes of graphs. Problem B. Find a good upper bound on csn. In this paper, we investigate problem A and determine cs(Gn), when Gn is a graph of order n with size two or three. Let Kn þ K1 be a disjoint union of the complete graph Kn with one isolated vertex, and K1 nþ1 be a complete graph Knþ1 by deleting n-1 edges from one vertex of K_n+1. We show that if \\\\\\\\\\\\\\\\lamda K_n+K1=cs(G_n), then G\\\\\\\\\\\\\\\'_n is isomorphic to K1 nþ1.