On the Signless Laplacian Eigenvalues and Optimum SLE of Graph
Subject Areas : Fuzzy Optimization and Modeling Journal
1 - Department of Pure Mathematics, Faculty of Mathematical Sciences, University of Kashan, Kashan, Iran
Keywords: Graph, Signless Laplacian Energy, Signless Laplacian Spectrum, Signless Laplacian Eigenvalues,
Abstract :
Let G be a graph of order n and with the vertex set {v_1,v_2,…,v_n } and the edge set E(G). The adjancency matrix of G is an n×n matrix A(G) whose (i,j)-entry is 1 if v_i is adjacent to v_j and 0, otherwise. Assume that D(G) is the n×n diagonal matrix whose (i,i)-entry is the degree of v_i. The matrices L(G) = D(G) - A(G) and Q(G) = D(G) + A(G) are called the Laplacian matrix and signless Laplacian matrix of G, respectively. The signelss Laplacian eigenvalues of a graph are the roots of characteristic polynomial of the signless Laplacian matrix of it. In this paper, we obtained signless Laplacian spectrum of some special subgraphs of complete graph and then estimated some bounds for signless Laplacian Energy of some graphs.