Modular curves and Néron models of generalized Jacobians

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Jordan, Bruce W., Ribet, Kenneth A., Scholl, Anthony J.
Format: Preprint
Published: 2022
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911869790322688
author Jordan, Bruce W.
Ribet, Kenneth A.
Scholl, Anthony J.
author_facet Jordan, Bruce W.
Ribet, Kenneth A.
Scholl, Anthony J.
contents Let $X$ be a smooth geometrically connected projective curve over the field of fractions of a discrete valuation ring $R$, and $\mathfrak{m}$ a modulus on $X$, given by a closed subscheme of $X$ which is geometrically reduced. The generalized Jacobian $J_\mathfrak{m}$ of $X$ with respect to $\mathfrak{m}$ is then an extension of the Jacobian of $X$ by a torus. We describe its Néron model, together with the character and component groups of the special fibre, in terms of a regular model of $X$ over $R$. This generalizes Raynaud's well-known description for the usual Jacobian. We also give some computations for generalized Jacobians of modular curves $X_0(N)$ with moduli supported on the cusps.
format Preprint
id arxiv_https___arxiv_org_abs_2207_13203
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Modular curves and Néron models of generalized Jacobians
Jordan, Bruce W.
Ribet, Kenneth A.
Scholl, Anthony J.
Algebraic Geometry
Number Theory
14K30 (Primary), 11G18, 14G35 (Secondary)
Let $X$ be a smooth geometrically connected projective curve over the field of fractions of a discrete valuation ring $R$, and $\mathfrak{m}$ a modulus on $X$, given by a closed subscheme of $X$ which is geometrically reduced. The generalized Jacobian $J_\mathfrak{m}$ of $X$ with respect to $\mathfrak{m}$ is then an extension of the Jacobian of $X$ by a torus. We describe its Néron model, together with the character and component groups of the special fibre, in terms of a regular model of $X$ over $R$. This generalizes Raynaud's well-known description for the usual Jacobian. We also give some computations for generalized Jacobians of modular curves $X_0(N)$ with moduli supported on the cusps.
title Modular curves and Néron models of generalized Jacobians
topic Algebraic Geometry
Number Theory
14K30 (Primary), 11G18, 14G35 (Secondary)
url https://arxiv.org/abs/2207.13203