English

Algebraic equations on the adelic closure of a Drinfeld module

Number Theory 2010-12-09 v1 Algebraic Geometry Logic

Abstract

Let kk be a field of positive characteristic and K=k(V)K = k(V) a function field of a variety VV over kk and let AK{\mathbf A}_K be a ring of ad\'{e}les of KK with respect to a cofinite set of the places on KK corresponding to the divisors on VV. Given a Drinfeld module Φ:F[t]EndK(Ga)\Phi:{\mathbb F}[t] \to \operatorname{End}_K({\mathbb G}_a) over KK and a positive integer gg we regard both KgK^g and AKg{\mathbf A}_K^g as Φ(Fp[t])\Phi({\mathbb F}_p[t])-modules under the diagonal action induced by Φ\Phi. For ΓKg\Gamma \subseteq K^g a finitely generated Φ(\Fp[t])\Phi(\F_p[t])-submodule and an affine subvariety X\bGagX \subseteq \bG_a^g defined over KK, we study the intersection of X(AK)X({\mathbf A}_K), the ad\`{e}lic points of XX, with barΓbar{\Gamma}, the closure of Γ\Gamma with respect to the ad\`{e}lic topology, showing under various hypotheses that this intersection is no more than X(K)ΓX(K) \cap \Gamma.

Keywords

Cite

@article{arxiv.1012.1825,
  title  = {Algebraic equations on the adelic closure of a Drinfeld module},
  author = {Dragos Ghioca and Thomas Scanlon},
  journal= {arXiv preprint arXiv:1012.1825},
  year   = {2010}
}
R2 v1 2026-06-21T16:55:32.974Z