Bounds for Behrend's conjecture on the canonical reduction
Abstract
Description
We prove Behrend's conjecture on the rationality of the canonical reduction of principal bundles and reductive group schemes for classical groups and give new bounds for the conjecture for exceptional groups. However we find a counterexample in the case of G_2-bundles in characteristic 2.
Erroneous claim about orthogonal bundles in characteristic 2 removed
Erroneous claim about orthogonal bundles in characteristic 2 removed