English

Semi-free subgroups of a profinite surface group

Group Theory 2018-04-24 v1

Abstract

We show that every closed normal subgroup of infinite index in a profinite surface group Γ\Gamma is contained in a semi-free profinite normal subgroup of Γ\Gamma. This answers a question of Bary-Soroker, Stevenson, and Zalesskii.

Keywords

Cite

@article{arxiv.1804.07800,
  title  = {Semi-free subgroups of a profinite surface group},
  author = {Matan Ginzburg and Mark Shusterman},
  journal= {arXiv preprint arXiv:1804.07800},
  year   = {2018}
}
R2 v1 2026-06-23T01:30:29.635Z