Abstract
For a simple connected graph G of order n, the normalized Laplacian is a square matrix of order n, defined as L(G) = D(G)(-1/2) L(G)D(G)(-1/2) where D(G)(-1/2) is the diagonal matrix whose i-th diagonal entry is 1/root d(i). In this paper, we find the normalized Laplacian di eigenvalues of the joined union of regular graphs in terms of the adjacency eigenvalues and the eigenvalues of quotient matrix associated with graph G. For a finite group G, the power graph P(G) of a group G is defined as the simple graph in which two distinct vertices are joined by an edge if and only if one is the power of the other. As a consequence of the joined union of graphs, we investigate the normalized Laplacian eigenvalues of the power graphs of the finite cyclic group Z(n).