English

Vertex-primitive s-arc-transitive digraphs of symplectic groups

Combinatorics 2024-08-23 v1 Group Theory

Abstract

A digraph is ss-arc-transitive if its automorphism group is transitive on directed paths with ss edges, that is, on ss-arcs. Although infinite families of finite ss-arc transitive digraphs of arbitrary valency were constructed by the third author in 1989, existence of a vertex-primitive 22-arc-transitive digraph was not known until an infinite family was constructed by the second author with Li and Xia in 2017. This led to a conjecture by the second author and Xia in 2018 that, for a finite vertex-primitive ss-arc-transitive digraph, ss is at most 22, together with their proof that it is sufficient to prove the conjecture for digraphs with an almost simple group of automorphisms. This paper confirms the conjecture for finite symplectic groups.

Keywords

Cite

@article{arxiv.2408.12074,
  title  = {Vertex-primitive s-arc-transitive digraphs of symplectic groups},
  author = {Lei Chen and Michael Giudici and Cheryl E. Praeger},
  journal= {arXiv preprint arXiv:2408.12074},
  year   = {2024}
}
R2 v1 2026-06-28T18:20:16.896Z