English

Varieties with prescribed finite unramified Brauer groups and subgroups precisely obstructing the Hasse principle

Number Theory 2025-07-09 v2 Algebraic Geometry

Abstract

On varieties defined over number fields, we consider obstructions to the Hasse principle given by subgroups of their Brauer groups. Given an arbitrary pair of non-zero finite abelian groups B0BB_0\subset B, we prove the existence of a variety XX such that its unramified Brauer group is isomorphic to BB and moreover B0B_0 is the smallest subgroup of BB that obstructs the Hasse principle. The concerned varieties are normic bundles over the projective line.

Keywords

Cite

@article{arxiv.2504.18293,
  title  = {Varieties with prescribed finite unramified Brauer groups and subgroups precisely obstructing the Hasse principle},
  author = {Yongqi Liang and Yufan Liu},
  journal= {arXiv preprint arXiv:2504.18293},
  year   = {2025}
}

Comments

24 pages, comments are welcome