A celebrated theorem of Bogomolov asserts that the $\ell$-adic Lie algebra attached to the Galois action on the Tate module of an abelian variety over a number field contains all homotheties. This is not the case in characteristic $p$: a ``counterexample" is provided by an ordinary elliptic curve defined over a finite field. In this note we discuss (and explicitly construct) more interesting examples of ``non-constant" absolutely simple abelian varieties (without homotheties) over global fields in characteristic $p$.
© 2008-2024 Fundación Dialnet · Todos los derechos reservados