4 papers
On some classes of bivalent and trivalent planar graphs
Jorge Alencar, Jean-Guy Caputo, Leonardo de Lima +1
A graph is called bivalent or trivalent if there exists an eigenvector of the graph Laplacian composed from {-1,1} or {-1,0,1}, respectively. These bivalent and trivalent eigenvect…
On graphs with eigenvectors in and the max -cut problem
Jorge Alencar, Leonardo de Lima, Vladimir Nikiforov
In this paper, we characterize all graphs with eigenvectors of the signless Laplacian and adjacency matrices with components equal to We extend the graph parameter…
An impossible utopia in distance geometry
Germano Abud, Jorge Alencar, Carlile Lavor +2
The Distance Geometry Problem asks for a realization of a given weighted graph in . Two variants of this problem, both originating from protein conformation, are base…
On graphs with adjacency and signless Laplacian matrix eigenvectors entries in
Jorge Alencar, Leonardo de Lima
Let be a simple graph. In 1986, Herbert Wilf asked what kind of graphs have an eigenvector with entries formed only by ? In this paper, we answer this question for the a…