Séminaires : Séminaire sur les Algèbres Enveloppantes

Equipe(s) :
Responsables :J.-Y. Charbonnel, R. Rentschler, M. Varagnolo
Email des responsables : Jean-Yves Charbonnel <jyc@math.jussieu.fr>, Rudolf Rentschler <rent@math.jussieu.fr>, Michela Varagnolo <varagnol@math.u-cergy.fr>
Salle : 175 rue du Chevaleret - 75013 Paris
Adresse :
Description

Orateur(s) Luca MOCI - Paris,
Titre Vector partition function and Dahmen-Micchelli modules: geometric realizations and duality.
Date07/03/2014
Horaire11:00 à 12:00
Diffusion
Résume(joint work with Francesco Cavazzani) In how many ways can a positive integer be expressed as a repeated sum of elements of a fixed list of positive integers? Generalizing this question, the vector partition function counts in how may ways a vector with integer coordinates can be written as a linear combination with nonnegative integer coefficients of the elements of a list of vectors with integer coordinates. This function is ``piecewise quasi-polynomial'', and its local pieces generate a module over the Laurent polynomials. We describe this and several related modules and algebras. Then we show that these modules and algebras can be``geometrically realized'' as the equivariant K-theory of some manifolds that have a nice combinatorial description.We also propose a more natural and general notion of duality between these modules, which corresponds to a Poincaré duality-type correspondence for equivariant K-theory.
Salle175 rue du Chevaleret - 75013 Paris
Adresse
© IMJ-PRG