English

Finiteness properties of torsion fields of abelian varieties

Number Theory 2024-07-02 v2 Algebraic Geometry

Abstract

Let AA be an abelian variety defined over a field K.K. We study finite generation properties of the profinite group Gal(Ω/K)\mathrm{Gal}(\Omega/K) and of certain closed normal subgroups thereof, where Ω\Omega is the torsion field of AA over KK. In fact, we establish more general finite generation properties for monodromy groups attached to smooth projective varieties via \'etale cohomology. We apply this in order to give an independent proof and generalizations of a recent result of Checcoli and Dill about small exponent subfields of Ω/K\Omega/K in the number field case. We also give an application of our finite generation results in the realm of permanence principles for varieties with the weak Hilbert property.

Keywords

Cite

@article{arxiv.2401.05805,
  title  = {Finiteness properties of torsion fields of abelian varieties},
  author = {Wojciech Gajda and Sebastian Petersen},
  journal= {arXiv preprint arXiv:2401.05805},
  year   = {2024}
}

Comments

17 pages. Slightly improved version now treating representations attached to 'etale cohomology as wee