Characterizing Abelian Varieties by the Reductions of the Mordell-Weil Group

Abstract

Let $A$ be an abelian variety defined over a number field $K$. If $\mathfrak{p}$ is a prime of $K$ of good reduction for $A$, let $A(K{)}_{\mathfrak{p}}$ denote the image of the Mordell-Weil group via reduction modulo $\mathfrak{p}$. We prove in particular that the size of $A(K{)}_{\mathfrak{p}}$, by varying $\mathfrak{p}$, encodes enough information to determine the $K$-isogeny class of $A$, provided that the following necessary condition is satisfied: $B(K)$ has positive rank for every non-trivial abelian subvariety $B$ of $A$. This is the analogue to a result by Faltings of 1983 considering instead the Hasse-Weil zeta function of the special fibers $A_{\mathfrak{p}}$.

References in corpus (2)

• Galois theory of iterated endomorphisms
• Prescribing valuations of the order of a point in the reductions of abelian varieties and tori