English

Principal bundles of reductive groups over affine schemes

Algebraic Geometry 2013-03-19 v2

Abstract

Let R be a semi-local regular domain containing an infinite perfect field k, and let K be the field of fractions of R. Let G be a reductive semi-simple simply connected R-group scheme such that each of its R-indecomposable factors is isotropic. We prove that for any Noetherian affine scheme A over k, the kernel of the map of etale cohomology sets H^1(A\times_k R,G)-> H^1(A\times_ k K,G), induced by the inclusion of R into K, is trivial. If R is the semi-local ring of several points on a k-smooth scheme, then it suffices to require that k is infinite and keep the same assumption concerning G.

Keywords

Cite

@article{arxiv.1204.1729,
  title  = {Principal bundles of reductive groups over affine schemes},
  author = {Ivan Panin and Anastasia Stavrova},
  journal= {arXiv preprint arXiv:1204.1729},
  year   = {2013}
}

Comments

This text has been incorporated into arXiv:0905.1418