English

More results on the distance (signless) Laplacian eigenvalues of graphs

Combinatorics 2017-05-23 v1

Abstract

Let GG be a connected graph with vertex set V(G)V(G) and edge set E(G)E(G). Let Tr(G)Tr(G) be the diagonal matrix of vertex transmissions of GG and D(G)D(G) be the distance matrix of GG. The distance Laplacian matrix of GG is defined as L(G)=Tr(G)D(G)\mathcal{L}(G)=Tr(G)-D(G). The distance signless Laplacian matrix of GG is defined as Q(G)=Tr(G)+D(G)\mathcal{Q}(G)=Tr(G)+D(G). In this paper, we give a lower bound on the distance Laplacian spectral radius in terms of D1D_1, as a consequence, we show that 1L(G)n+nω\partial_1^L(G)\geq n+\lceil\frac{n}{\omega}\rceil where ω\omega is the clique number of GG. Furthermore, we give some graft transformations, by using them, we characterize the extremal graph attains the maximum distance spectral radius in terms of nn and ω\omega. Moreover, we also give bounds on the distance signless Laplacian eigenvalues of GG, and give a confirmation on a conjecture due to Aouchiche and Hansen.

Keywords

Cite

@article{arxiv.1705.07419,
  title  = {More results on the distance (signless) Laplacian eigenvalues of graphs},
  author = {Jie Xue and Huiqiu Lin and Kinkar Ch. Das and Jinlong Shu},
  journal= {arXiv preprint arXiv:1705.07419},
  year   = {2017}
}