English

On graphs with adjacency and signless Laplacian matrix eigenvectors entries in $\{-1, +1\}$

Spectral Theory 2019-09-27 v1 Combinatorics

Abstract

Let GG be a simple graph. In 1986, Herbert Wilf asked what kind of graphs have an eigenvector with entries formed only by ±1\pm 1? In this paper, we answer this question for the adjacency, Laplacian and signless Laplacian matrix of a graph. Besides, we generalize the concept of an exact graph to the adjacency and signless Laplacian matrices. Infinity families of exact graphs for all those matrices are presented.

Keywords

Cite

@article{arxiv.1909.11860,
  title  = {On graphs with adjacency and signless Laplacian matrix eigenvectors entries in $\{-1, +1\}$},
  author = {Jorge Alencar and Leonardo de Lima},
  journal= {arXiv preprint arXiv:1909.11860},
  year   = {2019}
}