English

Vertex-primitive $s$-arc-transitive Cayley digraphs

Combinatorics 2026-05-05 v1 Group Theory

Abstract

Determining an upper bound on ss for vertex-primitive ss-arc-transitive digraphs has been an open problem of considerable interest since a question asked by Praeger in 1990. Although much progress has been made and an upper bound is conjectured to be 22, a complete classification for s=2s=2 remains out of reach. In this paper, we prove that the tight upper bound on ss for finite vertex-primitive ss-arc-transitive Cayley digraphs is exactly 22. Furthermore, we completely characterize the structure of these digraphs when s=2s=2.

Cite

@article{arxiv.2605.01734,
  title  = {Vertex-primitive $s$-arc-transitive Cayley digraphs},
  author = {Jing Jian Li and Yong Tang Shi and Yu Wang and Binzhou Xia},
  journal= {arXiv preprint arXiv:2605.01734},
  year   = {2026}
}

Comments

14 pages

R2 v1 2026-07-01T12:47:14.558Z