Norm one tori and Hasse norm principle
Abstract
Let be a field and be an algebraic -torus. In 1969, over a global field , Voskresenskii proved that there exists an exact sequence where is the kernel of the weak approximation of , is the Shafarevich-Tate group of , is a smooth -compactification of , , is the Picard group of and stands for the Pontryagin dual. On the other hand, in 1963, Ono proved that for the norm one torus of , if and only if the Hasse norm principle holds for . First, we determine for algebraic -tori up to dimension . Second, we determine for norm one tori with and . We also show that for when the Galois group of the Galois closure of is the Mathieu group with . Third, we give a necessary and sufficient condition for the Hasse norm principle for with and . As applications of the results, we get the group of -equivalence classes over a local field via Colliot-Th\'{e}l\`{e}ne and Sansuc's formula and the Tamagawa number over a number field via Ono's formula .
Cite
@article{arxiv.1910.01469,
title = {Norm one tori and Hasse norm principle},
author = {Akinari Hoshi and Kazuki Kanai and Aiichi Yamasaki},
journal= {arXiv preprint arXiv:1910.01469},
year = {2022}
}
Comments
To appear in Math. Comp., 98 pages