English

Hopfian Groups are Complete co-Analytic

Logic 2024-01-24 v2

Abstract

We show the set of Hopfian countable groups is a complete co-analytic subset of the standard Borel space of countable groups, resolving a question posed by Simon Thomas (https://doi.org/10.1007/s00153-017-0597-9).

Cite

@article{arxiv.2303.00839,
  title  = {Hopfian Groups are Complete co-Analytic},
  author = {Brian Pinsky},
  journal= {arXiv preprint arXiv:2303.00839},
  year   = {2024}
}

Comments

4 pages

R2 v1 2026-06-28T08:55:25.573Z