English

One-point covers of elliptic curves and good reduction

Algebraic Geometry 2017-07-31 v1 Number Theory

Abstract

Raynaud gave a criterion for a branched GG-cover of curves defined over a mixed-characteristic discretely valued field KK with residue characteristic pp to have good reduction in the case of either a three-point cover of P1\mathbb{P}^1 or a one-point cover of an elliptic curve. Specifically, such a cover has potentially good reduction whenever GG has a Sylow pp-subgroup of order pp and the absolute ramification index of KK is less than the number of conjugacy classes of order pp in GG. In the case of an elliptic curve, we generalize this to the case in which GG has an arbitrarily large cyclic Sylow pp-subgroup.

Keywords

Cite

@article{arxiv.1707.08996,
  title  = {One-point covers of elliptic curves and good reduction},
  author = {James Phillips},
  journal= {arXiv preprint arXiv:1707.08996},
  year   = {2017}
}

Comments

11 pages