3 citations · 3 across the 6 of their papers we have counts for
6 papers
Spectral upper bounds for the Grundy number of a graph
Thiago Assis, Gabriel Coutinho, Emanuel Juliano
The Grundy number of a graph is the minimum number of colors needed to properly color the graph using the first-fit greedy algorithm regardless of the initial vertex ordering. Comp…
Sums of squares of eigenvalues and the vector chromatic number
Gabriel Coutinho, Thomás Jung Spier
In this short paper we prove that the sum of the squares of negative (or positive) eigenvalues of the adjacency matrix of a graph is lower bounded by the sum of the degrees divided…
No perfect state transfer in trees with more than 3 vertices
Gabriel Coutinho, Emanuel Juliano, Thomás Jung Spier
We prove that the only trees that admit perfect state transfer according to the adjacency matrix model are and . This answers a question first asked by Godsil in 2012 an…
The spectrum of symmetric decorated paths
Gabriel Coutinho, Emanuel Juliano, Thomás Jung Spier
The main result of this paper states that in a rooted product of a path with rooted graphs which are disposed in a somewhat mirror-symmetric fashion, there are distinct eigenvalues…
Irrational quantum walks
Gabriel Coutinho, Pedro Ferreira Baptista, Chris Godsil +2
The adjacency matrix of a graph G is the Hamiltonian for a continuous-time quantum walk on the vertices of G. Although the entries of the adjacency matrix are integers, its eigenva…
Quantum walks do not like bridges
Gabriel Coutinho, Chris Godsil, Emanuel Juliano +1
We consider graphs with two cut vertices joined by a path with one or two edges, and prove that there can be no quantum perfect state transfer between these vertices, unless the gr…