4 papers
Hoffman colorability of graphs with smallest eigenvalue at least -2
Bart De Bruyn, Thijs van Veluw
In accordance with the Cameron-Goethals-Seidel-Shult Classification Theorem, we extend the characterization of Hoffman colorability of line graphs from (Abiad, Bosma, Van Veluw, 20…
The edge-isoperimetric number of graphs and their powers: approaches from spectral graph theory, optimization and finite geometry
Aida Abiad, Nils van de Berg, Emanuel Juliano +4
We obtain several sharp spectral bounds, approximations, and exact values for the isoperimetric number and related edge-expansion parameters of graphs. Our results focus on graph p…
Hoffman colorability of (strongly) regular graphs
Aida Abiad, Bart De Bruyn, Thijs van Veluw
Hoffman's bound is a well-known eigenvalue bound on the chromatic number of a graph. By interpreting this bound as a parameter, we show multiple applications of colorings attaining…
Hoffman colorings of graphs
Aida Abiad, Wieb Bosma, Thijs van Veluw
Hoffman's bound is a well-known spectral bound on the chromatic number of a graph, known to be tight for instance for bipartite graphs. While Hoffman colorings (colorings attaining…