32 citations · 47 across the 8 of their papers we have counts for
4 papers · 1 filter
Reduction of structure for torsors over semilocal rings
V. Chernousov, Ph. Gille, Z. Reichstein
Let G be a reductive affine group scheme defined over a semilocal ring k. Assume that either G is semisimple or k is normal and noetherian. We show that G has a finite k-subgroup S…
A lower bound on the essential dimension of a connected linear group
Philippe Gille, Zinovy Reichstein
Let G be a connected linear algebraic group defined over an algebraically closed field k and H be a finite abelian subgroup of G whose order is prime to char(k). We show that the e…
Tame group actions on central simple algebras
Zinovy Reichstein, Nikolaus Vonessen
We study actions of linear algebraic groups on finite-dimensional central simple algebras. We describe the fixed algebra for a broad class of such actions.
Essential dimension and algebraic stacks
Patrick Brosnan, Zinovy Reichstein, Angelo Vistoli
We define and study the essential dimension of an algebraic stack. We compute the essential dimension of the stacks Mgn and MgnBar of smooth, or stable, n-pointed curves of genus g…