Picard rank jumps for K3 surfaces with bad reduction
Number Theory
2024-12-11 v2 Algebraic Geometry
Abstract
Let be a K3 surface over a number field. We prove that has infinitely many specializations where its Picard rank jumps, hence extending our previous work with Shankar--Shankar--Tang to the case where might have potentially bad reduction. We prove a similar result for generically ordinary non-isotrivial families of K3 surfaces over curves over which extends previous work of Maulik--Shankar--Tang. As a consequence, we give a new proof of the ordinary Hecke orbit conjecture for orthogonal and unitary Shimura varieties.
Keywords
Cite
@article{arxiv.2203.09559,
title = {Picard rank jumps for K3 surfaces with bad reduction},
author = {Salim Tayou},
journal= {arXiv preprint arXiv:2203.09559},
year = {2024}
}
Comments
Minor revisions. To appear in Algebra & Number Theory