English

Brauer groups and \'etale homotopy type

Algebraic Geometry 2020-12-29 v1

Abstract

Extending a result of Schr\"oer on a Grothendieck question in the context of complex analytic spaces, we prove that the surjectivity of the Brauer map δ:Br(X)Heˊt2(X,Gm,X)tor\delta: Br(X) \rightarrow H_{\rm \'et}^2(X,\mathbb{G}_{m, X})_{\rm tor} for algebraic schemes depends on their \'etale homotopy type. We use properties of algebraic K(π,1)K(\pi, 1) spaces to apply this to some classes of proper and smooth algebraic schemes. In particular we recover a result of Hoobler and Berkovich for abelian varieties. Further, we give an additional condition for the surjectivity of δ\delta which involves pro-universal covers. All proposed conditions turn out to be equivalent for smooth quasi-projective varieties.

Keywords

Cite

@article{arxiv.2012.14277,
  title  = {Brauer groups and \'etale homotopy type},
  author = {Mohammed Moutand},
  journal= {arXiv preprint arXiv:2012.14277},
  year   = {2020}
}

Comments

27 pages, comments are welcome

R2 v1 2026-06-23T21:29:38.470Z