Groupe d’études et de recherche en analyse des décisions


An Inequality for the Signless Laplacian Index of a Graph Using the Chromatic Number


Let Q = D + A denote the signless Laplacian matrix of a graph G of order n, where D is the diagonal matrix of the degrees and A the adjacency matrix of G. Let q1 denote the index of Q and the chromatic number of G. In this note we prove that .

, 10 pages