Pseudospectrum Energy of Graphs

Abstract

Let G be a simple graph of order N, the concept of resol-vent energy of graph G; i.e. ER(G)=sum_{i=1}^N (N - λi)^{-1} was established in Resolvent Energy of Graphs, MATCH commun. Math. comput. chem., 75 (2016), 279-290. In this paper we study the set of resol-vents energies of graph G which it is called pseudospectrum energy of graph PS(G). For large value resolvent energy of graph ER(G) and real eigenvalues, we establish a number of properties of PS(G): For complex eigenvalues, some examples of PS(G) are given.