Finiteness of the Tate-Shafarevich group over function fields for groups of multiplicative type
Number Theory
2026-07-16 v1 Algebraic Geometry
Abstract
Let be the function field of a smooth geometrically integral variety of dimension over a field of characteristic 0 and be the set of discrete valuations of associated with the prime divisors on . We show that if is a -defined group of multiplicative type, then the corresponding Tate-Shafarevich group is finite in the following situations: (1) is finitely generated and ; (2) is a number field. This complements previous work of Harari and Szamuely, which considered the case where is a curve.
Cite
@article{arxiv.2607.15372,
title = {Finiteness of the Tate-Shafarevich group over function fields for groups of multiplicative type},
author = {Igor A. Rapinchuk and Avinash Roy},
journal= {arXiv preprint arXiv:2607.15372},
year = {2026}
}