Calcul symbolique et propagation des singularités pour les équations aux dérivées partielles non linéaires
We consider a linear parabolic transmission problem across an interface of codimension one in a bounded domain or on a Riemannian manifold, where the transmission conditions involve an additional parabolic operator on the interface. This system is an idealization of a three-layer model in which the central layer has a small thickness . We prove a Carleman estimate in the neighborhood of the interface for an associated elliptic operator by means of partial estimates in several microlocal regions....
In this paper we consider a smooth and bounded domain of dimension with boundary and we construct sequences of solutions to the wave equation with Dirichlet boundary condition which contradict the Strichartz estimates of the free space, providing losses of derivatives at least for a subset of the usual range of indices. This is due to microlocal phenomena such as caustics generated in arbitrarily small time near the boundary. Moreover, the result holds for microlocally strictly convex domains...
L’article reprend systématiquement la théorie des cycles proches pour les -modules holonomes. La théorie est étendue aux complexes, et l’on obtient une équivalence de catégories entre complexes monodromiques et complexes spécialisables (ces derniers, sur le complété de pour la filtration). On obtient en particulier les théorèmes de commutation par rapport à la dualité, aux images inverses lisses et aux images directes propres qu’il était naturel d’espérer.