$h^1\ne h_1$ for Anderson t-motives
Number Theory
2021-01-05 v3
Abstract
Let be an Anderson t-motive of dimension and rank . Associated are two -modules , of dimensions , - analogs of , for an abelian variety . There is a theorem (Anderson): ; in this case is called uniformizable. It is natural to expect that always . Nevertheless, we explicitly construct a counterexample. Further, we answer a question of D.Goss: is it possible that two Anderson t-motives that differ only by a nilpotent operator are of different uniformizability type, i.e. one of them is uniformizable and other not? We give an explicit example that this is possible.
Cite
@article{arxiv.1807.08675,
title = {$h^1\ne h_1$ for Anderson t-motives},
author = {Aleksandr Grishkov and Dmitry Logachev},
journal= {arXiv preprint arXiv:1807.08675},
year = {2021}
}
Comments
31 pages. Minor improvements