Le problème de Cauchy ramifié linéaire pour des données à singularités algébriques
Nous précisons, dans le contexte microlocal Sobolev, les résultats de propagations de singularités obtenus par N. Hanges dans le contexte microlocal pour les opérateurs pseudo-differentiels à symbole principal réel et dont la variété caractéristique est la réunion de deux hypersurfaces lisses d’intersection non involutive. Nous obtenons également un résultat de propagation dans un cas non linéaire. Nos démonstrations consistent essentiellement à étudier l’action des paramétrices constantes par...
Building on the theory of elliptic operators, we give a unified treatment of the following topics: - the problem of homotopy invariance of Novikov’s higher signatures on closed manifolds, - the problem of cut-and-paste invariance of Novikov’s higher signatures on closed manifolds, - the problem of defining higher signatures on manifolds with boundary and proving their homotopy invariance.
Let be a complex manifold with strongly pseudoconvex boundary . If is a defining function for , then is plurisubharmonic on a neighborhood of in , and the (real) 2-form is a symplectic structure on the complement of in a neighborhood of in ; it blows up along . The Poisson structure obtained by inverting extends smoothly across and determines a contact structure on which is the same as the one induced by the complex structure. When is compact, the Poisson structure near...
In this paper we prove a variety of results about the signature operator on Witt spaces. First, we give a parametrix construction for the signature operator on any compact, oriented, stratified pseudomanifold which satisfies the Witt condition. This construction, which is inductive over the ‘depth’ of the singularity, is then used to show that the signature operator is essentially self-adjoint and has discrete spectrum of finite multiplicity, so that its index—the analytic signature of —is well-defined....
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