EnglishFrançais

Site Web DMA

Bannière DMA Site de l'ENS Site Paris Sciences et Lettres Site du CNRS Accueil

Séminaire Géométrie et théorie des modèles

Horaires : Le vendredi 10 mars 2017, 16h

Lieu : ENS, salle W

Satellites of spherical subgroups and Poincaré polynomials

Anne Moreau (Lille)

Let G be a connected reductive group over C. One can associate with every spherical homogeneous space G/H its lattice of weights X^*(G/H) and a subset S of M of linearly independent primitive lattice vectors which are called the spherical roots. For any subset I of S we define, up to conjugation, a spherical subgroup H_I in G such that dim H_I = dim H and X^*(G/H_I) = X^*(G/H). We call the subgroups H_I the satellites of the spherical subgroup H. Our interest in satellites H_I is motivated by the space of arcs of the spherical homogeneous space G/H. We show a close relation between the Poincaré polynomials of the two spherical homogeneous spaces G/H and G/H_I. All of this is useful for the computation of the stringy E-function of Q-Gorenstein spherical embeddings. The talk is based on joint works with Victor Batyrev.

 

Autres séances du séminaire


45 rue d'Ulm - F 75230 PARIS cedex 05 | phone : (33) 1 44 32 20 49 | fax : (33) 1 44 32 20 69

Plan du site | Mentions légales | | Edition du site | Web site designed under SPIP