Saeed Mohammadian Semnani - Department of Mathematics, Faculty of Mathematics, Statistics and Computer Sciences, Semnan University, Semnan, Iran.

If L(G) is the line graph of G, it is difficult to get the adjacency matrix of Lt(G)=L(L(L ... L(G))); t≥۳ and also its spectrum. In this paper, we present a formula to compute the spectrum of Lt(G), for each positive integer t, where G is a regular graph.

Line graph, Simple graph, Adjacency matrix, Eigenvalue of a matrix, Characteristic polynomial, Spectra of a graph