# 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) Francesco SALA - Heriot-Watt University and Maxwell Institute for Mathematical Sciences, Titre Hall algebras and sheaves on surfaces Date 19/02/2016 Horaire 10:30 à 11:30 Résume Hall algebras play a prominent role in the interactions between algebraic geometry and representation theory. Recently, refined'' versions of them, called K-theoretic Hall algebras, were introduced by Schiffmann and Vasserot. They have notable connections with the geometric Langlands correspondence, the theory of quantum groups and gauge theories. In the first part of the talk, I will give an overview of the theory of Hall algebras. In the second part, I will describe some (new) examples of K-theoretic Hall algebras. These algebras are related to some stacks of a certain kind of sheaves on noncompact surfaces. (Work in progress with Olivier Schiffmann.) Salle salle 2015, 2em étage, Adresse Sophie Germain