On the Signless Laplacian Spectral Radius of Graphs without Small Books and Intersecting Quadrangles

Abstract

In this paper, we determine the maximum signless Laplacian spectral radius of all graphs which do not contain small books as a subgraph and characterize all extremal graphs. In addition, we give an upper bound of the signless Laplacian spectral radius of all graphs which do not contain intersecting quadrangles as a subgraph.

Keywords

• forbidden subgraphs
• signless Laplacian matrix
• signless Laplacian spectral radius
• extremal graphs