Séminaires : Séminaire Groupes, Représentations et Géométrie

 Equipe(s) : gr, Responsables : A. Brochier, O. Brunat, J.-Y. Charbonnel, O. Dudas, E. Letellier, D. Juteau, M. Varagnolo, E. Vasserot Email des responsables : Adrien Brochier , Olivier Brunat , Jean-Yves Charbonnel , Olivier Dudas , Emmanuel Letellier , Daniel Juteau , Michela Varagnolo , Eric Vasserot Salle : salle 2015, 2em étage, Adresse : Sophie Germain Description

 Orateur(s) Leonardo PATIMO - Albert-Ludwigs-Universität Freiburg, Titre Dyck partitions and the intersection cohomology of Schubert varieties Date 21/06/2019 Horaire 14:00 à 15:00 Résume The cohomology of Schubert varieties is a very classical object of study, and we can understand it thoroughly thanks to a crucial tool: its Schubert basis. From a representation theory point of view, it is often more natural to look instead at the intersection cohomology of this varieties. However, understanding the intersection cohomology is in general a much more difficult task. In this talk we will focus on Schubert varieties inside Grassmannians, which have many special features among Schubert varieties. The related Kazhdan-Lusztig polynomials, in fact, can be realized combinatorially: we can compute them by counting certain Dyck partitions. In this talk we will explain how, by lifting'' the rich combinatorics of this Dyck partitions to the category of singular Soergel bimodules we are able to extend the Schubert basis to a basis of the intersection cohomology. Salle salle 2015, 2em étage, Adresse Sophie Germain