English

Difference sets disjoint from a subgroup II: groups of order $4p^2$

Group Theory 2021-03-19 v1 Combinatorics

Abstract

We study finite groups GG having a normal subgroup HH and DGH,DD1=,D \subset G \setminus H, D \cap D^{-1}=\emptyset, such that the multiset {xy1:x,yD}\{ xy^{-1}:x,y \in D\} has every non-identity element occur the same number of times (such a DD is called a {\it DRAD difference set}). We show that there are no such groups of order 4p24p^2, where pp is an odd prime.

Keywords

Cite

@article{arxiv.2103.09892,
  title  = {Difference sets disjoint from a subgroup II: groups of order $4p^2$},
  author = {Stephen P. Humphries and Nathan L. Nicholson},
  journal= {arXiv preprint arXiv:2103.09892},
  year   = {2021}
}

Comments

15 pages

R2 v1 2026-06-24T00:17:27.899Z