English

Rigidity and unlikely intersections for formal groups

Number Theory 2019-01-15 v2

Abstract

Let K be a p-adic field and let F and G be two formal groups over O_K. We prove that if F and G have infinitely many torsion points in common, then F=G. This follows from a rigidity result: any bounded power series that sends infinitely many torsion points of F to torsion points of F is an endomorphism of F.

Keywords

Cite

@article{arxiv.1811.05824,
  title  = {Rigidity and unlikely intersections for formal groups},
  author = {Laurent Berger},
  journal= {arXiv preprint arXiv:1811.05824},
  year   = {2019}
}

Comments

v2: various clarifications. 8 pages

R2 v1 2026-06-23T05:15:21.594Z