English

The nonabelian product modulo sum

Group Theory 2025-10-22 v2 Logic

Abstract

It is shown that if {Hn}nω\{H_n\}_{n \in \omega} is a sequence of groups without involutions, with 1<Hn201 < |H_n| \leq 2^{\aleph_0}, then the topologist's product modulo the finite words is (up to isomorphism) independent of the choice of sequence. This contrasts with the abelian setting: if {An}nω\{A_n\}_{n \in \omega} is a sequence of countably infinite torsion-free abelian groups, then the isomorphism class of the product modulo sum nωAn/nωAn\prod_{n \in \omega} A_n/\bigoplus_{n \in \omega} A_n is dependent on the sequence.

Keywords

Cite

@article{arxiv.2206.02682,
  title  = {The nonabelian product modulo sum},
  author = {Samuel M. Corson},
  journal= {arXiv preprint arXiv:2206.02682},
  year   = {2025}
}
R2 v1 2026-06-24T11:40:42.991Z