On SL(2)-actions without 3-dimensional orbits
On spherical nilpotent orbits and beyond
We continue investigations that are concerned with the complexity of nilpotent orbits in semisimple Lie algebras. We give a characterization of the spherical nilpotent orbits in terms of minimal Levi subalgebras intersecting them. This provides a kind of canonical form for such orbits. A description minimal non-spherical orbits in all simple Lie algebras is obtained. The theory developed for the adjoint representation is then extended to Vinberg’s -groups. This yields a description of spherical...
On spinor varieties and their secants.
On symmetric semialgebraic sets and orbit spaces
For a symmetric (= invariant under the action of a compact Lie group G) semialgebraic basic set C, described by s polynomial inequalities, we show, that C can also be written by s + 1 G-invariant polynomials. We also describe orbit spaces for the action of G by a number of inequalities only depending on the structure of G.
On the derived categories of coherent sheaves on some homogeneous spaces.
On the fundamental group of the complement of a divisor in a homogeneous space.
On the Hasse principle for homogeneous spaces with finite stabilizers
On the motive of a quotient variety.
We show that the motive of the quotient of a scheme by a finite group coincides with the invariant submotive.
On the Periods of Enriques Surfaces. II.
On the Shintani zeta function for the space of binary quadratic forms.
On the stability of subgroup actions on certain quasihomogeneous -varieties.
Operateurs differentiels de Shimura et espaces prehomogenes.
-adic Whittaker functions and vector bundles on flag manifolds
p-adic deformations of cohomology classes of subgroups of GL (N,Z).
P-Adic Homogeneous Spaces and Moduli Problems.
Partial resolutions of quotient singularities.
Peirce-Zerlegungen und Jordan-Strukturen zu homogenen Kegeln.
Piecewise polynomial functions, convex polytopes and enumerative geometry
Pinceaux de droites et automorphismes des surfaces affines.
Plongements d'espaces homogènes.