Existential definability and diophantine stability
arXiv:2208.09963
Abstract
Let be a number field, let be an algebraic (possibly infinite degree) extension of , and let be their rings of integers. Suppose is an abelian variety defined over such that is infinite and is a torsion group. If at least one of the following conditions is satisfied: 1. is a number field, 2. is totally real, 3. is a quadratic extension of a totally real field, then has a diophantine definition over .
We corrected a minor mistake. We are grateful to Laurent Moret-Bailly for pointing it out