Split degenerate superelliptic curves and $\ell$-adic images of inertia

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Yelton, Jeffrey
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908316518580224
author Yelton, Jeffrey
author_facet Yelton, Jeffrey
contents Let $K$ be a field with a discrete valuation, and let $p$ and $\ell$ be (possibly equal) primes which are not necessarily different from the residue characteristic. Given a superelliptic curve $C : y^p = f(x)$ which has split degenerate reduction over $K$, with Jacobian denoted by $J / K$, we describe the action of an element of the inertia group $I_K$ on the $\ell$-adic Tate module $T_\ell(J)$ as a product of powers of certain transvections with respect to the $\ell$-adic Weil pairing and the canonical principal polarization of $J$. The powers to which the transvections are taken are given by a formula depending entirely on the cluster data of the roots of the defining polynomial $f$. This result is demonstrated using Mumford's non-archimedean uniformization of the curve $C$.
format Preprint
id arxiv_https___arxiv_org_abs_2504_00205
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Split degenerate superelliptic curves and $\ell$-adic images of inertia
Yelton, Jeffrey
Number Theory
11G10, 11G20, 14K25, 11G07
Let $K$ be a field with a discrete valuation, and let $p$ and $\ell$ be (possibly equal) primes which are not necessarily different from the residue characteristic. Given a superelliptic curve $C : y^p = f(x)$ which has split degenerate reduction over $K$, with Jacobian denoted by $J / K$, we describe the action of an element of the inertia group $I_K$ on the $\ell$-adic Tate module $T_\ell(J)$ as a product of powers of certain transvections with respect to the $\ell$-adic Weil pairing and the canonical principal polarization of $J$. The powers to which the transvections are taken are given by a formula depending entirely on the cluster data of the roots of the defining polynomial $f$. This result is demonstrated using Mumford's non-archimedean uniformization of the curve $C$.
title Split degenerate superelliptic curves and $\ell$-adic images of inertia
topic Number Theory
11G10, 11G20, 14K25, 11G07
url https://arxiv.org/abs/2504.00205