English

An infinite class of Neumaier graphs and non-existence results

Combinatorics 2021-09-30 v1

Abstract

A Neumaier graph is a non-complete edge-regular graph containing a regular clique. A Neumaier graph that is not strongly regular is called a strictly Neumaier graph. In this work we present a new construction of strictly Neumaier graphs, and using Jacobi sums, we show that our construction produces infinitely many instances. Moreover, we prove some necessary conditions for the existence of (strictly) Neumaier graphs that allow us to show that several parameter sets are not admissible.

Keywords

Cite

@article{arxiv.2109.14281,
  title  = {An infinite class of Neumaier graphs and non-existence results},
  author = {Aida Abiad and Wouter Castryck and Maarten De Boeck and Jack H. Koolen and Sjanne Zeijlemaker},
  journal= {arXiv preprint arXiv:2109.14281},
  year   = {2021}
}