Computing isogenies from modular equations in genus two

Bibliographic Details
Title: Computing isogenies from modular equations in genus two
Authors: Jean Kieffer, Aurel Page, Damien Robert
Contributors: Kieffer, Jean
Source: Journal of Algebra. 666:331-386
Publication Status: Preprint
Publisher Information: Elsevier BV, 2025.
Publication Year: 2025
Subject Terms: Algorithm, Mathematics - Algebraic Geometry, Mathematics - Number Theory, Modular equations, Isogenies, [MATH.MATH-AG] Mathematics [math]/Algebraic Geometry [math.AG], FOS: Mathematics, Number Theory (math.NT), Abelian surfaces, 0101 mathematics, 01 natural sciences, Algebraic Geometry (math.AG), [MATH.MATH-NT] Mathematics [math]/Number Theory [math.NT]
Description: We present an algorithm solving the following problem: given two genus 2 curves over a field k with isogenous Jacobians, compute such an isogeny explicitly. This isogeny can be either an l-isogeny or, in the real multiplication case, an isogeny with cyclic kernel; we require that k have large enough characteristic and that the curves be sufficiently generic. Our algorithm uses modular equations for these isogeny types, and makes essential use of an explicit Kodaira--Spencer isomorphism in genus 2.
Document Type: Article
File Description: application/pdf
Language: English
ISSN: 0021-8693
DOI: 10.1016/j.jalgebra.2024.11.029
DOI: 10.48550/arxiv.2001.04137
Access URL: http://arxiv.org/abs/2001.04137
https://hal.science/hal-02436133v3/document
https://hal.science/hal-02436133v3
https://doi.org/10.1016/j.jalgebra.2024.11.029
Rights: Elsevier TDM
arXiv Non-Exclusive Distribution
Accession Number: edsair.doi.dedup.....ff4601e4ed6db61cfbc6afc78bfc12f9
Database: OpenAIRE
Description
ISSN:00218693
DOI:10.1016/j.jalgebra.2024.11.029