Upper Bounds for the Signless Laplacian Spectral Radius of Graphs on Surfaces


Xiaodan Chen, Yaoping Hou




In this paper, we present some new upper bounds for the signless Laplacian spectral radius of graphs embeddable on a fixed surface, which improve several previously known results. We also give several improved upper bounds for the signless Laplacian spectral radius of outerplanar graphs and Halin graphs.