English

Neumaier graphs from cyclotomy with small coherent rank

Combinatorics 2025-04-17 v1

Abstract

Using cyclotomy, we construct a new infinite family of Neumaier graphs that includes infinitely many strongly regular graphs. Notably, this family conjecturally contains infinitely many graphs with coherent rank 66. Our construction also provides the first known examples that answer a question posed by Evans, Goryainov, and Panasenko regarding the existence of Neumaier graphs whose nexus is not a power of 22. In addition, we show that a construction of Greaves and Koolen yields an infinite family of Neumaier graphs with coherent rank 66.

Keywords

Cite

@article{arxiv.2504.12026,
  title  = {Neumaier graphs from cyclotomy with small coherent rank},
  author = {Gary R. W. Greaves and Zhao Kuang Tan},
  journal= {arXiv preprint arXiv:2504.12026},
  year   = {2025}
}

Comments

25 pages

R2 v1 2026-06-28T23:00:27.819Z