English

Zero-loci of Brauer group elements on semi-simple algebraic groups

Number Theory 2018-10-09 v2 Algebraic Geometry

Abstract

We consider the problem of counting the number of rational points of bounded height in the zero-loci of Brauer group elements on semi-simple algebraic groups over number fields. We obtain asymptotic formulae for the counting problem for wonderful compactifications using the spectral theory of automorphic forms. Applications include asymptotic formulae for the number of matrices over Q whose determinant is a sum of two squares. These results provide a positive answer to some cases of a question of Serre concerning such counting problems.

Keywords

Cite

@article{arxiv.1705.09244,
  title  = {Zero-loci of Brauer group elements on semi-simple algebraic groups},
  author = {Daniel Loughran and Ramin Takloo-Bighash and Sho Tanimoto},
  journal= {arXiv preprint arXiv:1705.09244},
  year   = {2018}
}

Comments

35 pages. Added more details and fixed typos. Final version

R2 v1 2026-06-22T19:59:08.469Z