Rank 2 local systems and abelian varieties
Abstract
Let be a smooth geometrically connected variety. Inspired by work of Corlette-Simpson over , we formulate a conjecture that absolutely irreducible rank 2 local systems with infinite monodromy on come from families of abelian varieties. When is a projective variety, we prove a Lefschetz-style theorem for abelian schemes of -type on , modeled after a theorem of Simpson. If one assumes a strong form of Deligne's (-adic) \emph{companions conjecture} from Weil II, this implies that our conjecture for projective varieties also reduces to the case of projective curves. We also answer affirmitavely a question of Grothendieck on extending abelian schemes via their -divisible groups.
Cite
@article{arxiv.1809.02106,
title = {Rank 2 local systems and abelian varieties},
author = {Raju Krishnamoorthy and Ambrus Pál},
journal= {arXiv preprint arXiv:1809.02106},
year = {2021}
}
Comments
29 pages, comments very welcome. v3: completely reorganized, minor errors fixed. v4: final version