100, rue des maths 38610 Gières / GPS : 45.193055, 5.772076 / Directeur : Thierry Gallay

Dans le cadre des mesures de confinement destinées à lutter contre le Covid-19, le bâtiment de l'Institut Fourier est actuellement fermé et sous alarme, pour une durée indéterminée. Toutes les activités scientifiques prévues à court terme sont donc annulées ou reportées.
---------------------------------------------------------------------------------
 
 

Ivan Moyano

Uncertainty and localisation properties for the spectrum of the Laplacian on compact and noncompact settings
Lundi, 2 Mars, 2020 - 13:30
Résumé : 

In this talk I will consider the spectral resolution of the   Laplacian operator on a manifold and discuss the question of how   spectral projectors can concentrate on a given subset of the manifold.  
In particular we will consider two cases : compact manifolds with or  without boundary in which the purely discrete spectrum leads to finite  combinations of eigenfunctions and the unbounded case without  boundaries, in which the spectrum contains a continous part. In both  cases we give quantitative estimates for the localisation of the spectral projection in terms of the highest frequnecy involved, which  are essentially optimal. We also try to refine the uncertainty  principle in this situation so as to consider the smallest possible  localisation sets, which can be of not too small Hausdorff content.  This is based on joint work with G. Lebeau (Nice) and N. Burq (Orsay).

Institution de l'orateur : 
Université de Nice
Thème de recherche : 
Physique mathématique
Salle : 
1, tour IRMA
logo uga logo cnrs