English

Identifying normal and congruence subgroups

Number Theory 2015-01-06 v1

Abstract

We give a simple algorithm that enables us to determine whether a subgroup of finite index of the Hecke group is normal.

Keywords

Cite

@article{arxiv.1501.00743,
  title  = {Identifying normal and congruence subgroups},
  author = {Cheng Lien Lang and Mong Lung Lang},
  journal= {arXiv preprint arXiv:1501.00743},
  year   = {2015}
}
R2 v1 2026-06-22T07:50:35.924Z