English

Computing algebraic Belyi functions on Bring's curve

Number Theory 2025-07-01 v3 Algebraic Geometry Complex Variables

Abstract

In this paper, we explicitly compute two kinds of algebraic Belyi functions on Bring's curve. One is related to a congruence subgroup of SL2(Z){\rm SL}_2(\mathbb{Z}) and the other is related to a congruence subgroup of the triangle group Δ(2,4,5)\SL2(R)\Delta(2,4,5)\subset \SL_2(\R). To carry out the computation, we use elliptic cusp forms of weight 2 for the former case and the automorphism group of Bring's curve for the latter case. We also discuss a suitable base field (a number field) for describing isomorphisms between Hulek-Craig's curve, Bring's curve, and another algebraic model obtained as a modular curve.

Cite

@article{arxiv.2503.23780,
  title  = {Computing algebraic Belyi functions on Bring's curve},
  author = {Madoka Horie and Takuya Yamauchi},
  journal= {arXiv preprint arXiv:2503.23780},
  year   = {2025}
}

Comments

10 pages

R2 v1 2026-06-28T22:40:06.157Z