English

Models for quotients of modular curves

Number Theory 2021-07-13 v2

Abstract

We describe an algorithm for computing a \Q\Q-rational model for the quotient of a modular curve by an automorphism group, under mild assumptions on the curve and the automorphisms, by determining qq-expansions for a basis of the corresponding space of cusp forms. We also give a moduli interpretation for general morphisms between modular curves.

Keywords

Cite

@article{arxiv.2101.03797,
  title  = {Models for quotients of modular curves},
  author = {Josha Box},
  journal= {arXiv preprint arXiv:2101.03797},
  year   = {2021}
}