English

The index formula for the Hecke group H_5

Group Theory 2014-05-27 v3

Abstract

The present article gives the index formula of the principal congruence subgroups of the Hecke group H_5

Keywords

Cite

@article{arxiv.1401.0775,
  title  = {The index formula for the Hecke group H_5},
  author = {Cheng Lien Lang and Mong Lung Lang},
  journal= {arXiv preprint arXiv:1401.0775},
  year   = {2014}
}

Comments

The current version includes a proof of the fact that the commutator subgroup of H_5 is not congruence