Elliptic mod \ell Galois representations which are not minimally elliptic
Number Theory
2016-09-07 v2
Abstract
In a recent preprint, F. Calegari has shown that for and 7 there exist 2-dimensional surjective representations of with values in coming from the -torsion points of an elliptic curve defined over , but not minimally, i.e., so that any elliptic curve giving rise to has prime-to- conductor greater than the (prime-to-) conductor of . In this brief note, we will show that the same is true for any prime , concretely, we will show that for any such the elliptic curve is semistable, has bad reduction at 3, the associated Galois representation is surjective, unramified at 3, and there is no elliptic curve with good reduction at 3 whose associated representation is isomorphic to .
Keywords
Cite
@article{arxiv.math/0409115,
title = {Elliptic mod \ell Galois representations which are not minimally elliptic},
author = {Luis Dieulefait},
journal= {arXiv preprint arXiv:math/0409115},
year = {2016}
}