Problème aux limites pour le système de Vlasov-Maxwell
On s’intéresse à la résolution du système de Navier-Stokes incompressible à densité variable dans le demi-espace en dimension On considère des données initiales à régularité critique. On établit que si la densité initiale est proche d’une constante strictement positive dans et si la vitesse initiale est petite par rapport à la viscosité dans l’espace de Besov homogène alors le système de Navier-Stokes admet une unique solution globale. La démonstration repose sur de nouvelles estimations...
We consider sequences of solutions of the Navier-Stokes equations in , associated with sequences of initial data bounded in . We prove, in the spirit of the work of H.Bahouri and P.Gérard (in the case of the wave equation), that they can be decomposed into a sum of orthogonal profiles, bounded in , up to a remainder term small in ; the method is based on the proof of a similar result for the heat equation, followed by a perturbation–type argument. If is an “admissible” space (in particular ...
A new, shorter, proof of the Treves theorem on an algebraic criterion for the first integrals of the KdV hierarchy is given, along with an addition to the theorem.
In this paper, we prove propagation estimates for a massive Dirac equation in flat spacetime. This allows us to construct the asymptotic velocity operator and to analyse its spectrum. Eventually, using this new information, we are able to obtain complete scattering results; that is to say we prove the existence and the asymptotic completeness of the Dollard modified wave operators.