Les opérateurs pseudo-différentiels classiques et leurs conjugués par changement de variable
The purpose of this talk is to present some recent results about the Cauchy theory of the gravity water waves equations (without surface tension). In particular, we clarify the theory as well in terms of regularity indexes for the initial conditions as fin terms of smoothness of the bottom of the domain (namely no regularity assumption is assumed on the bottom). Our main result is that, following the approach developed in [1, 2], after suitable para-linearizations, the system can be arranged into...
This paper contains some new results on lower bounds for pseudo-differential operators whose symbols do not remain positive. Non-negativity of averages of the symbol on canonical images of the unit ball is sufficient to get a Gårding type inequality for Schrödinger operators with magnetic potential and one dimensional pseudo-differential operators.
In this note we are going to address the question of when a second order differential operator is controlled by a subelliptic second order differential operator.
On étudie une classe de microdistributions intégrales de Fourier représentées à l’aide de phases homogènes analytiques réelles, d’amplitudes qui sont des réalisations holomorphes tronquées de symboles analytiques classiques, et de contours d’intégration le long desquels la partie imaginaire de la phase a une propriété convenable de positivité. On donne des théorèmes de changement de phase et de composition transverse analogues à ceux du cas , et on montre comment le calcul symbolique standard des...
We obtain sufficient conditions for nonexistence of nontrivial solutions for some classes of nonlinear partial differential inequalities containing the fractional powers of the Laplace operator.