No CrossRef data available.
Published online by Cambridge University Press: 08 September 2023
Let $p$ be a prime number, $k$ a finite field of characteristic $p>0$ and $K/k$ a finitely generated extension of fields. Let $A$ be a $K$-abelian variety such that all the isogeny factors are neither isotrivial nor of $p$-rank zero. We give a necessary and sufficient condition for the finite generation of $A(K^{\mathrm {perf}})$ in terms of the action of $\mathrm {End}(A)\otimes \mathbb {Q}_p$ on the $p$-divisible group $A[p^{\infty }]$ of $A$. In particular, we prove that if $\mathrm {End}(A)\otimes \mathbb {Q}_p$ is a division algebra, then $A(K^{\mathrm {perf}})$ is finitely generated. This implies the ‘full’ Mordell–Lang conjecture for these abelian varieties. In addition, we prove that all the infinitely $p$-divisible elements in $A(K^{\mathrm {perf}})$ are torsion. These reprove and extend previous results to the non-ordinary case.
The author would like to thank A. Cadoret, B. Kahn, C. Gasbarri and A. Shiho for useful discussions and G. Ancona for many suggestions on how to improve the exposition. The author is grateful to an anonymous referee whose suggestions helped to improve the exposition and the clarity of the paper and for pointing out the work of Trihan which greatly simplified the proof of Proposition 4.1.2. Part of this work has been done when the author was a guest of the Max Planck Institute for Mathematics (MPIM) in Bonn and he would like to express his gratitude to the MPIM for their hospitality and financial support.