English

Galois representations attached to elliptic curves with complex multiplication

Number Theory 2022-08-17 v3

Abstract

The goal of this article is to give an explicit classification of the possible pp-adic Galois representations that are attached to elliptic curves EE with CM defined over Q(j(E))\mathbb{Q}(j(E)). More precisely, let KK be an imaginary quadratic field, and let OK,f\mathcal{O}_{K,f} be an order in KK of conductor f1f\geq 1. Let EE be an elliptic curve with CM by OK,f\mathcal{O}_{K,f}, such that EE is defined by a model over Q(j(E))\mathbb{Q}(j(E)). Let p2p\geq 2 be a prime, let GQ(j(E))G_{\mathbb{Q}(j(E))} be the absolute Galois group of Q(j(E))\mathbb{Q}(j(E)), and let ρE,p ⁣:GQ(j(E))GL(2,Zp)\rho_{E,p^\infty}\colon G_{\mathbb{Q}(j(E))}\to \operatorname{GL}(2,\mathbb{Z}_p) be the Galois representation associated to the Galois action on the Tate module Tp(E)T_p(E). The goal is then to describe, explicitly, the groups of GL(2,Zp)\operatorname{GL}(2,\mathbb{Z}_p) that can occur as images of ρE,p\rho_{E,p^\infty}, up to conjugation, for an arbitrary order OK,f\mathcal{O}_{K,f}.

Keywords

Cite

@article{arxiv.1809.02584,
  title  = {Galois representations attached to elliptic curves with complex multiplication},
  author = {Álvaro Lozano-Robledo},
  journal= {arXiv preprint arXiv:1809.02584},
  year   = {2022}
}

Comments

55 pages. Updated after referee reports. To appear in "Algebra and Number Theory"

R2 v1 2026-06-23T03:58:17.460Z