English

Generators for the level $m$ congruence subgroups of braid groups

Group Theory 2024-09-17 v1 Geometric Topology

Abstract

We prove for m1m\geq1 and n5n\geq5 that the level mm congruence subgroup Bn[m]B_n[m] of the braid group BnB_n associated to the integral Burau representation BnGLn(Z)B_n\to\mathrm{GL}_n(\mathbb{Z}) is generated by mmth powers of half-twists and the braid Torelli group. This solves a problem of Margalit, generalizing work of Assion, Brendle--Margalit, Nakamura, Stylianakis and Wajnryb.

Keywords

Cite

@article{arxiv.2409.09612,
  title  = {Generators for the level $m$ congruence subgroups of braid groups},
  author = {Ishan Banerjee and Peter Huxford},
  journal= {arXiv preprint arXiv:2409.09612},
  year   = {2024}
}

Comments

12 pages, 0 figures

R2 v1 2026-06-28T18:44:59.789Z