Distributive properties of division points and discriminants of Drinfeld modules
Abstract
We present a new notion of distribution and derived distribution of rank for a global function field with a distinguished place . It allows to describe the relations between division points, isogenies, and discriminants both for a fixed Drinfeld module of rank for the above data, or for the corresponding modular forms. We introduce and study three basic distributions with values in , in the group of roots of unity in the algebraic closure of , and in the group of -units of the completed algebraic closure of , respectively. There result product formulas for division points and discriminants that encompass known results (e.g. analogues of Wallis' formula for in the rank- case, of Jacobi's formula in the rank- case, and similar boundary expansions for ) and several new ones: the definition of a canonical discriminant for the most general case of Drinfeld modules and the description of the sizes of division and discriminant forms. In the now classical case where and , or , we give explicit values for the logarithms of such forms.
Keywords
Cite
@article{arxiv.2402.00545,
title = {Distributive properties of division points and discriminants of Drinfeld modules},
author = {Ernst-Ulrich Gekeler},
journal= {arXiv preprint arXiv:2402.00545},
year = {2024}
}
Comments
32 pages, comments welcome