English

A note on factorizations of finite groups

Group Theory 2021-10-15 v1

Abstract

In Question 19.35 of the Kourovka Notebook, M. H. Hooshmand asks whether, given a finite group GG and a factorization card(G)=n1nk\mathrm{card}(G)= n_1\ldots n_k, one can always find subsets A1,,AkA_1,\ldots,A_k of GG with card(Ai)=ni\mathrm{card}(A_i)=n_i such that G=A1Ak;G=A_1\ldots A_k; equivalently, such that the group multiplication map A1××AkGA_1\times\ldots\times A_k\to G is a bijection. We show that for GG the alternating group on 4 elements, k=3k=3, and (n1,n2,n3)=(2,3,2)(n_1,n_2,n_3) = (2,3,2), the answer is negative. We then generalize some of the tools used in our proof, and note an open question.

Keywords

Cite

@article{arxiv.2003.12866,
  title  = {A note on factorizations of finite groups},
  author = {George M. Bergman},
  journal= {arXiv preprint arXiv:2003.12866},
  year   = {2021}
}

Comments

3 pages. Copy at http://math.berkeley.edu/~gbergman/papers may be updated more frequently than arXiv copy

R2 v1 2026-06-23T14:30:26.630Z