Hensel-lifting torsion points on Jacobians and Galois representations

Nicolas Mascot

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arXiv · 1808.03939

Hensel-lifting torsion points on Jacobians and Galois representations

Nicolas Mascot

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Abstract

Let $\rho$ be a mod $\ell$ Galois representation. We show how to compute $\rho$, given the characteristic polynomial of the image of the Frobenius at one prime $p$ and a curve $C$ whose Jacobian contains $\rho$ in its $\ell$-torsion. The main ingredient is a method to $p$-adically lift torsion points on a Jacobian in the framework of Makdisi's algorithms.

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Nicolas Mascot. 2018-08-12. Hensel-lifting torsion points on Jacobians and Galois representations. https://arxiv.org/abs/1808.03939

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