3 papers
math.CO2026
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…
math.CO2025
Divisible design graphs with selfloops
Anwita Bhowmik, Bart De Bruyn, Sergey Goryainov
We develop a basic theory for divisible design graphs with possible selfloops (LDDG's), and describe two infinite families of such graphs, some members of which are also classical…
math.CO2020
Neumaier graphs with few eigenvalues
Aida Abiad, Bart De Bruyn, Jozefien D'haeseleer +1
A Neumaier graph is a non-complete edge-regular graph containing a regular clique. In this paper we give some sufficient and necessary conditions for a Neumaier graph to be strongl…