English

The commutator subgroups of free groups and surface groups

Geometric Topology 2022-07-19 v2 Group Theory

Abstract

A beautifully simple free generating set for the commutator subgroup of a free group was constructed by Tomaszewski. We give a new geometric proof of his theorem, and show how to give a similar free generating set for the commutator subgroup of a surface group. We also give a simple representation-theoretic description of the structure of the abelianizations of these commutator subgroups and calculate their homology.

Keywords

Cite

@article{arxiv.2101.05905,
  title  = {The commutator subgroups of free groups and surface groups},
  author = {Andrew Putman},
  journal= {arXiv preprint arXiv:2101.05905},
  year   = {2022}
}

Comments

20 pages, 4 figures; minor revision; to appear in Enseign. Math

R2 v1 2026-06-23T22:11:16.117Z