English

Typically bounding torsion on elliptic curves with rational $j$-invariant

Number Theory 2021-11-23 v2

Abstract

A family F\mathcal{F} of elliptic curves defined over number fields is said to be typically bounded in torsion if the torsion subgroups E(F)[E(F)[tors]] of those elliptic curves E/FFE_{/F}\in \mathcal{F} can be made uniformly bounded after removing from F\mathcal{F} those whose number field degrees lie in a subset of Z+\mathbb{Z}^+ with arbitrarily small upper density. For every number field FF, we prove unconditionally that the family EF\mathcal{E}_F of elliptic curves defined over number fields and with FF-rational jj-invariant is typically bounded in torsion. For any integer dZ+d\in\mathbb{Z}^+, we also strengthen a result on typically bounding torsion for the family Ed\mathcal{E}_d of elliptic curves defined over number fields and with degree dd jj-invariant.

Keywords

Cite

@article{arxiv.2102.10417,
  title  = {Typically bounding torsion on elliptic curves with rational $j$-invariant},
  author = {Tyler Genao},
  journal= {arXiv preprint arXiv:2102.10417},
  year   = {2021}
}

Comments

17 pages, to appear in Journal of Number Theory