activity
20172022
most citedColouring the normalized Laplacian

7 citations · 11 across the 6 of their papers we have counts for

collaborators

11 papers

quant-ph20221 cited

Why and how to add direction to a quantum walk

Rodrigo Chaves, Bruno Oliveira Chagas, Gabriel Coutinho

We formalize the treatment of directed (or chiral) quantum walks using Hermitian adjacency matrices, bridging two developing fields of research in quantum information and spectral…

math.CO2020

Fundamentals of fractional revival in graphs

Ada Chan, Gabriel Coutinho, Whitney Drazen +6

We develop a general spectral framework to analyze quantum fractional revival in quantum spin networks. In particular, we introduce generalizations of the notions of cospectral and…

math.CO20197 cited

Colouring the normalized Laplacian

Gabriel Coutinho, Rafael Grandsire, Célio Passos

We apply Cauchy's interlacing theorem to derive some eigenvalue bounds to the chromatic number using the normalized Laplacian matrix, including a combinatorial characterization of…

math.CO2019

Algebras, graphs and thetas

Marcel K. de Carli Silva, Gabriel Coutinho, Chris Godsil +1

We extend the clique-coclique inequality, previously known to hold for graphs in association schemes and vertex-transitive graphs, to graphs in homogeneous coherent configurations…

math.CO2019

Dual Hoffman Bounds for the Stability and Chromatic Numbers Based on SDP

Nathan Benedetto Proença, Marcel K. de Carli Silva, Gabriel Coutinho

The notion of duality is a key element in understanding the interplay between the stability and chromatic numbers of a graph. This notion is a central aspect in the celebrated theo…

math.CO20191 cited

Fractional Revival and Association Schemes

Ada Chan, Gabriel Coutinho, Christino Tamon +2

Fractional revival occurs between two vertices in a graph if a continuous-time quantum walk unitarily maps the characteristic vector of one vertex to a superposition of the charact…