3 papers
math.CO2024
Main -eigenvalues of quasi-threshold graphs
Átila Jones, Vilmar Trevisan, Cybele T. M. Vinagre
In this note, we present a structural description of certain connected cographs having main signless Laplacian eigenvalues. This result allows us to characterize the cog…
cs.DM2016
Cograph generation with linear delay
Átila A. Jones, Fábio Protti, Renata R. Del-Vecchio
Cographs have always been a research target in areas such as coloring, graph decomposition, and spectral theory. In this work, we present an algorithm to generate all unlabeled cog…
cs.DM2016
Laplacian integrality in P4-sparse and P4-extendible graphs
Renata Del-Vecchio, Atila Jones
Let G be a simple graph and L = L(G) the Laplacian matrix of G. G is called L-integral if all its Laplacian eigenvalues are integer numbers. It is known that every cograph, a graph…