Abelian varieties with isogenous reductions
arXiv:2009.01435
Abstract
If A and B are abelian varieties over a number field K such that there are non-trivial geometric homomorphisms of abelian varieties between reductions of A and B at most primes of K, then there exists a non-trivial (geometric) homomorphism from A to B defined over an algebraic closure of K.
Final version, with French abstract; to appear in Comptes Rendus - Série Mathématique