6 papers
On the generalized Bass--Quillen conjecture in dimension 2
Anastasia Stavrova
Let be a regular ring of dimension . Let be a reductive group over such that its derived group is a split, i.e. a Chevalley--Demazure, semisimple group. We prove…
Non-Stable -Functors of Discrete Valuation Rings Containing a Field
Philippe Gille, Anastasia Stavrova
Let be a field, and let be a simply connected semisimple k-group which is isotropic and contains a strictly proper parabolic -subgroup . Let be a discrete valuati…
R-equivalence on group schemes
Philippe Gille, A Stavrova
We define R-equivalence for group schemes over a semilocal ring and relate this with rational properties. Two main cases are investigated: tori and isotropic semisimple simply conn…
On a theorem of Harder
Ivan Panin, Anastasia Stavrova
We prove that for any simply connected isotropic reductive group G over a Dedekind domain D, any Zariski-locally trivial principal G-bundle over D is trivial. The corresponding res…
On the Gille theorem for the relative projective line
Ivan Panin, Anastasia Stavrova
Let be a Noetherian separated scheme. Let be a reductive -group scheme, and let be a principal -bundle over . We prove that if the restriction of…
Chevalley groups over Laurent polynomial rings
Anastasia Stavrova
Let be a simply connected Chevalley--Demazure group scheme without -factors. For any unital commutative ring , we denote by the standard elementary subgroup of…