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arXiv · 2604.08146

A Simpler Approach to a Descent Conjecture of Wittenberg

Yisheng Tian
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Abstract

A descent conjecture of Wittenberg [Wit24, Conjecture 3.7.4] predicts that if all the twists of a rationally connected torsor over a smooth base satisfy weak approximation with Brauer-Manin obstruction, then so does the base. We give an alternative proof of Wittenberg's conjecture for certain torsors under connected linear groups via Cao's descent formula.

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Yisheng Tian. 2026-04-09. A Simpler Approach to a Descent Conjecture of Wittenberg. https://arxiv.org/abs/2604.08146

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