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Bibliographic Details
Main Author: Faber, Xander
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2407.12089
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author Faber, Xander
author_facet Faber, Xander
contents Let $K$ be a complete discretely valued field. An extension $L/K$ is "weakly totally ramified" if the residue extension is purely inseparable. We sharpen a result of Ax by showing that any Galois-invariant disk in the algebraic closure of $K$ contains an element that generates a separable weakly totally ramified extension. As an application, we prove that elliptic curves and dynamical systems on $\mathbb{P}^1$ achieve semistable reduction over a separable weakly totally ramified extension of the base field. We also obtain several arithmetic consequences for torsion points on elliptic curves and preperiodic points for dynamical systems.
format Preprint
id arxiv_https___arxiv_org_abs_2407_12089
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Ramified Approximation and Semistable Reduction
Faber, Xander
Number Theory
Let $K$ be a complete discretely valued field. An extension $L/K$ is "weakly totally ramified" if the residue extension is purely inseparable. We sharpen a result of Ax by showing that any Galois-invariant disk in the algebraic closure of $K$ contains an element that generates a separable weakly totally ramified extension. As an application, we prove that elliptic curves and dynamical systems on $\mathbb{P}^1$ achieve semistable reduction over a separable weakly totally ramified extension of the base field. We also obtain several arithmetic consequences for torsion points on elliptic curves and preperiodic points for dynamical systems.
title Ramified Approximation and Semistable Reduction
topic Number Theory
url https://arxiv.org/abs/2407.12089