The automorphism group of torsion points of an elliptic curve over a field of characteristic $\ge 5$
For a field $\mathbb{K}$ of characteristic $p\ge5$ containing $\mathbb{F}_{p}^{\operatorname{alg}}$ and the elliptic curve $E_{s,t}: y^{2} = x^{3} + sx + t$ defined over the function field $\mathbb{K}\left(s,t\right)$ of two variables $s$ and $t$, we prove that for a non-negative positive integer $e$ and a positive integer $N$ which is not divisible by $p$, the automorphism group of the normal extension $\mathbb{K}\left(s,t\right)\left(E_{s,t}\left[p^{e} N\right]\right)$ over $\mathbb{K}\left(s,t\right)$ is isomorphic to $\left(\mathbb{Z}/p^{e}\mathbb{Z}\right)^{\times} \times \operatorname{SL}_{2} \left(\mathbb{Z}/N\mathbb{Z}\right)$.
Publication Details
- Journal
- ArXiv.org
- Published
- 2025-04-21
- Primary Topic
- Algebraic Geometry and Number Theory
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Research Foundation
- National Research Foundation of Korea
- Ministry of Science and ICT, South Korea
- National Science and Technology Council