215 citations · 807 across the 39 of their papers we have counts for
5 papers · 1 filter
Complexity of actions over perfect fields
Friedrich Knop, Vladimir S. Zhgoon
Let be a connected reductive group over a perfect field acting on an algebraic variety and let be a minimal parabolic subgroup of . For -spherical -varieti…
On the W-action on B-sheets in positive characteristic
Friedrich Knop, Guido Pezzini
Let G be a connected reductive group defined over an algebraically closed ground field of characteristic p, let B be a Borel subgroup of G, and let X be a G-variety. The first name…
Invariant functions on symplectic representations
Friedrich Knop
Let G be a connected reductive group. In this paper we are studying the invariant theory of symplectic G-modules. Our main result is that the invariant moment map is equidimensiona…
Classification of smooth affine spherical varieties
Friedrich Knop, Bart Van Steirteghem
Let G be a complex reductive group. A normal G-variety X is called spherical if a Borel subgroup of G has a dense orbit in X. Of particular interest are spherical varieties which a…
A connectedness property of algebraic moment maps
Friedrich Knop
Let a connected reductive group G act on the smooth connected variety X. The cotangent bundle of X is a Hamiltonian G-variety. We show that its "total moment map" has connected fib…