English

Almost all standard double covers of abelian Cayley graphs have smallest possible automorphism groups

Combinatorics 2026-01-29 v1 Group Theory

Abstract

The standard double cover of a graph Γ\Gamma is the direct product Γ×K2\Gamma\times K_2. A graph Γ\Gamma is said to be stable if all the automorphisms of Γ×K2\Gamma\times K_2 come from its factors. Although the study of stability has attracted significant attention, particularly regarding Cayley graphs of abelian groups, a complete classification remains elusive even for Cayley graphs of cyclic groups. In this paper, we study the asymptotic enumeration of both labeled and unlabeled Cayley graphs of abelian groups whose standard double cover has the smallest possible automorphism group. As a corollary, in both the labeled and unlabeled settings, we conclude that the proportion of stable Cayley graphs of an abelian group of order rr approaches 11 as rr\rightarrow\infty, proving that almost all Cayley graphs of finite abelian groups are stable.

Keywords

Cite

@article{arxiv.2601.20214,
  title  = {Almost all standard double covers of abelian Cayley graphs have smallest possible automorphism groups},
  author = {Binzhou Xia and Zhishuo Zhang and Shasha Zheng},
  journal= {arXiv preprint arXiv:2601.20214},
  year   = {2026}
}