Congruence Subgroup Property for nilpotent groups and subsurface subgroups of Mapping Class Groups
Group Theory
2024-12-03 v2 Geometric Topology
Abstract
We prove the Congruence Subgroup Property for two families of subgroups of Mapping Class Groups of finite-type surfaces. The first one is related to nilpotent quotients of the fundamental group and Johnson filtration, and along the way we give an elementary proof of a theorem of Ben-Ezra-Lubotzky. The second family consists of certain geometric subgroups obtained via subsurface inclusions.
Cite
@article{arxiv.2411.06867,
title = {Congruence Subgroup Property for nilpotent groups and subsurface subgroups of Mapping Class Groups},
author = {Adam Klukowski},
journal= {arXiv preprint arXiv:2411.06867},
year = {2024}
}
Comments
20 pages, 4 figures; updated with some important references