English

Modular curves $X_0(N)$ of density degree $5$

Number Theory 2026-02-20 v2

Abstract

We determine all modular curves X0(N)X_0(N) with density degree 55, i.e. all curves X0(N)X_0(N) with infinitely many points of degree 55 and only finitely many points of degree d4d\leq4. As a consequence, the problem of determining all curves X0(N)X_0(N) with infinitely many points of degree 55 remains open for only 3030 levels NN.

Keywords

Cite

@article{arxiv.2503.08975,
  title  = {Modular curves $X_0(N)$ of density degree $5$},
  author = {Maarten Derickx and Wontae Hwang and Daeyeol Jeon and Petar Orlić},
  journal= {arXiv preprint arXiv:2503.08975},
  year   = {2026}
}

Comments

25 pages. Revised version