I will show that continous cohomology (with coefficients twisted by a unnitary representation) of an automorphism group of a building vanish under certain conditions in certain dimensions. This provides a large new family of Kazhdan groups.
--Exceptionnellement a 14h30 --
M. Christian KRATTENTHALER est candidat sur un poste PR a Strasbourg
EXPOSE ANNULE / EXPOSE ANNULE / EXPOSE ANNULE / EXPOSE ANNULE / EXPOSE ANNULE / EXPOSE ANNULE
Thà`eme : Finance et Probabilités.
* M KUENZER est visiteur pour un mois * En raison du colloquium prevu de M Landsberg de 16h a 17h, l'expose de M KUENZER risque de commencer avec 5 mn de retard.
Débute exceptionnellement à 16h15.
M. GECK est candidat sur un poste de PR à Strasbourg.
En raison du colloquium de M. Geck, le seminaire commencera avec 10 mn de retard.
M. KRIKORIAN est candidat sur un poste de PR à Strasbourg.
En raison du colloquium de Raphael Krikorian, l'expose commencera avec 10 minutes de retard
Point de vue historique et description d'une étude expérimentale auprès d'étudiants de première année universitaire (informations plus détaillées sur affiche IREM).
Premier d'une série de plusieurs exposés.
M. Dominique COLLOMBIER est candidat à un poste de PR à Strasbourg.
E. PEYRE est candidat à un poste de PR à Strasbourg.
Ce séminaire commencera exceptionnellement à 16h15 au lieu de 16h habituellement.
In 1981, Brockett and Byrnes showed how the static feedback laws = which control a given linear system are determined through the Schubert = calculus of enumerative geometry. This talk will describe that connection and propose numerical homotopy methods to solve the resulting systems of polynomials. The related questions of finding real feedback laws and of trying to=20 do Schubert's calculus over the real numbers are intertwined with a precise conjecture of Shapiro and Shapiro. We discuss a new result = which shows it is possible to do Schubert's calculus over the reals and proves = a version of this conjecture. In a similar vein, problems of enumerating rational curves in the Grassmannian (also known as quantum enumerative=20 geometry) may also be solved over the real numbers.
I discuss some consequences of the following Fernando's result. Let g be a finite-dimensional Lie algebras, M be an irreducible g-module, g[M] be the set of elements which act locally finitely on M. Then g[M] is a subalgebra of g. For example, if M is finite-dimensional then g[M]=g, if M is a Verma module over semisimple g then g[M] is a Borel subalgera, if M is a Harish-Chandra module then the subalgebra g[M] is the set of fixed points of some involution of g. The main part of the talk concerns the following question: how to characterize the subalgebras k of g which can be realized as g[M] for irreducible g-modules M. We will see that not all subalgebras can be realized this way and answer the question for solvable subalgebras in a semisimple g. We also discuss the relation of above question with geometry of K-orbits on G/B and D-modules. This is a joint work with I. Dimitrov and I. Penkov.
I will show that continous cohomology (with coefficients twisted by a unnitary representation) of an automorphism group of a building vanish under certain conditions in certain dimensions. This provides a large new family of Kazhdan groups.
In this talk I review some of the classical tricks, such as Van der Corput's method, random dynamics, topologizing measurable spaces, graphical independence etc, which have been used by Bergelson and others in the analysis of recurrence in ergodic dynamical systems. When combined with the theory of disjointness and dynamical factorisation developed by Furstenberg and others, these simple ideas help to prove difficult theorems about multiple recurrence, polynomial recurrence and other problems of distribution.
Attention a l'horaire inhabituel.
3 exposés sur le thème :"Topological Hochschild homology, topological and algebraic approaches".
3 exposés sur le thème :"Topological Hochschild homology, topological and algebraic approaches".
Séminaire exceptionnellement décalé.
*** LIEU ET HEURE INHABITUELS ***
**** Attention : LIEU ET HEURE INHABITUELS ****
Attention : jour et heure inhabituels
-- Attention : changement exceptionnel de date --
-- Attention : Changement d'horaire car 2 séminaires cet apres-midi ! --
- Attention : Changement exceptionnel de jour -
In this talk we will explore some of the striking interactions between convex, metric, integral, and symplectic geometry that arise from the study of Finsler manifolds.
JOUR ET HORAIRE INHABITUELS