English

Modular invariants and isogenies

Number Theory 2019-02-28 v5

Abstract

We provide explicit bounds on the difference of heights of the jj-invariants of isogenous elliptic curves defined over Q\overline{\mathbb{Q}}. The first one is reminiscent of a classical estimate for the Faltings height of isogenous abelian varieties, which is indeed used in the proof. We also use an explicit version of Silverman's inequality and isogeny estimates by Gaudron and R\'emond. We give applications to the study of V\'elu's formulas and of modular polynomials.

Keywords

Cite

@article{arxiv.1611.01094,
  title  = {Modular invariants and isogenies},
  author = {Fabien Pazuki},
  journal= {arXiv preprint arXiv:1611.01094},
  year   = {2019}
}
R2 v1 2026-06-22T16:41:11.334Z