English

Unramified cohomology of classifying varieties for exceptional simply connected groups

Algebraic Geometry 2009-05-23 v1

Abstract

Let BG be a classifying variety for an exceptional simple simply connected algebraic group G. We compute the degree 3 unramified Galois cohomology of BG with values in Q/Z(2) over an arbitrary field F. Combined with a paper by Merkurjev, this completes the computation of these cohomology groups for G semisimple simply connected over all fields. These computations provide another example of a simple simply connected group G such that BG is not stably rational.

Keywords

Cite

@article{arxiv.math/0304270,
  title  = {Unramified cohomology of classifying varieties for exceptional simply connected groups},
  author = {R. Skip Garibaldi},
  journal= {arXiv preprint arXiv:math/0304270},
  year   = {2009}
}