English

A characterization of exceptional pseudocyclic association schemes by multidimensional intersection numbers

Combinatorics 2020-08-11 v1

Abstract

Recent classification of 32\frac{3}{2}-transitive permutation groups leaves us with three infinite families of groups which are neither 22-transitive, nor Frobenius, nor one-dimensional affine. The groups of the first two families correspond to special actions of PSL(2,q){\mathrm{PSL}}(2,q) and PΓL(2,q),{\mathrm{P\Gamma L}}(2,q), whereas those of the third family are the affine solvable subgroups of AGL(2,q){\mathrm{AGL}}(2,q) found by D. Passman in 1967. The association schemes of the groups in each of these families are known to be pseudocyclic. It is proved that apart from three particular cases, each of these exceptional pseudocyclic schemes is characterized up to isomorphism by the tensor of its 33-dimensional intersection numbers.

Keywords

Cite

@article{arxiv.2008.04006,
  title  = {A characterization of exceptional pseudocyclic association schemes by multidimensional intersection numbers},
  author = {Gang Chen and Jiawei He and Ilia Ponomarenko and Andrey Vasil'ev},
  journal= {arXiv preprint arXiv:2008.04006},
  year   = {2020}
}

Comments

16 pages

R2 v1 2026-06-23T17:44:42.778Z