On a Galois property of fields generated by the torsion of an abelian variety

In this article, we study a certain Galois property of subextensions of k(A_tors), the minimal field of definition of all torsion points of an abelian variety A defined over a number field k. Concretely, we show that each subfield of k(A_tors) that is Galois over k (of possibly infinite degree) and whose Galois group has finite exponent is contained in an abelian extension of some finite extension of k. As an immediate corollary of this result and a theorem of Bombieri and Zannier, we deduce that each such field has the Northcott property, that is, does not contain any infinite set of algebraic numbers of bounded height.