Quelques applications de la cohomologie d'intersection
Quelques propriétés des espaces homogènes sphèriques.
Quiver varieties and Weyl group actions
The cohomology of Nakajima’s varieties is known to carry a natural Weyl group action. Here this fact is established using the method of intersection cohomology, in analogy with the definition of Springer’s representations.
Quotient de la variété des points infiniment voisins d’ordre 9 sous l’action de
Quotient Singularities which are Complete Intersections.
Quotients for algebraic group actions over non-algebraically closed fields.
Quotients of toric varieties.
Quotients of toric varieties by actions of subtori
Let X be an algebraic toric variety with respect to an action of an algebraic torus S. Let Σ be the corresponding fan. The aim of this paper is to investigate open subsets of X with a good quotient by the (induced) action of a subtorus T ⊂ S. It turns out that it is enough to consider open S-invariant subsets of X with a good quotient by T. These subsets can be described by subfans of Σ. We give a description of such subfans and also a description of fans corresponding to quotient varieties. Moreover,...