English

On graph Laplacian eigenvectors with components in {-1,0,1}

Spectral Theory 2018-11-19 v2 Combinatorics

Abstract

We characterize all graphs for which there are eigenvectors of the graph Laplacian having all their components in {-1,+1} or {-1,0,+ 1}. Graphs having eigenvectors with components in {-1,+1} are called bivalent and are shown to be the regular bipartite graphs and their extensions obtained by adding edges between vertices with the same value for the given eigenvector. Graphs with eigenvectors with components in {-1,0,+ 1} are called trivalent and are shown to be soft-regular graphs -graphs such that vertices associated with non-zero components have the same degree- and their extensions via some transformations.

Keywords

Cite

@article{arxiv.1806.00072,
  title  = {On graph Laplacian eigenvectors with components in {-1,0,1}},
  author = {J-G. Caputo and I. Khames and A. Knippel},
  journal= {arXiv preprint arXiv:1806.00072},
  year   = {2018}
}

Comments

Keywords: Algebraic graph theory. Graph spectra and applications. Graph Laplacian

R2 v1 2026-06-23T02:15:19.776Z