English

Dihedral groups of square-free order are DCI-groups

Group Theory 2025-09-04 v1

Abstract

A finite group GG is a called a DCI-group if any two isomorphic Cayley digraphs of GG are also isomorphic via an automorphism of GG. If GG is a non-abelian generalised dihedral DCI-group, then Dobson, Muzychuk, and Spiga proved that GG must be a dihedral group of square-free order (Ars Math. Contemp., 2022). In this paper, we prove that the converse statement also holds, i.\,e., all dihedral groups of square-free order are DCI-groups.

Keywords

Cite

@article{arxiv.2509.02778,
  title  = {Dihedral groups of square-free order are DCI-groups},
  author = {István Kovács and Gábor Somlai},
  journal= {arXiv preprint arXiv:2509.02778},
  year   = {2025}
}