Perfect points of abelian varieties
Abstract
Let be an algebraic extension of and a regular extension of fields (e.g. ). Let be a -abelian variety such that all the isogeny factors are neither isotrivial nor of -rank zero. We give a necessary and sufficient condition for the finite generation of in terms of the action of on the -divisible group of . In particular we prove that if is a division algebra then is finitely generated. This implies the "full" Mordell-Lang conjecture for these abelian varieties. In addition we prove that all the infinitely -divisible elements in are torsion. These reprove and extend previous results to the non ordinary case. One of the main technical intermediate result is an overconvergence theorem for the Dieudonn\'e module of certain semiabelian schemes over smooth varieties.
Cite
@article{arxiv.2103.16568,
title = {Perfect points of abelian varieties},
author = {Emiliano Ambrosi},
journal= {arXiv preprint arXiv:2103.16568},
year = {2023}
}
Comments
v3: 16 pages, shortened and final version. To appear in Compositio Mathematica. Some of the results in Part II will appear elsewhere. v2: minor edits. v1:37 pages, comments are very welcome