Démonstration géométrique du théorème de Lang-Néron

Abstract

We give a proof without heights of the Lang-Néron theorem: if $K/k$ is a regular extension of finite type and $A$ is an abelian $K$-variety, the group $A(K)/\Tr_{K/k} A(k)$ is finitely generated, where $\Tr_{K/k} A$ denotes the $K/k$-trace of $A$ in the sense of Chow. Our method computes the rank of this group in terms of certain ranks of Néron-Severi groups.