The defect of weak approximation for a reductive group over a global field
Representation Theory
2025-08-22 v8 Algebraic Geometry
Group Theory
Number Theory
Abstract
We compute the defect of weak approximation for a reductive group G over a global field K in terms of the algebraic fundamental group of G.
Keywords
Cite
@article{arxiv.2406.08017,
title = {The defect of weak approximation for a reductive group over a global field},
author = {Mikhail Borovoi and Jean-Louis Colliot-Thélène},
journal= {arXiv preprint arXiv:2406.08017},
year = {2025}
}
Comments
v7: 27 pages, including the listing of a Magma program; v8: 29 pages, including an appendix by J.-L. Colliot-Th\'el\`ene