| 21/10/2021 | | | | 14h | | | | Salle de conférences | | |
| | Cyril Letrouit (DMA (ENS)) | | | | Propagation of singularities in subelliptic PDEs | | | | In this talk, we consider the wave equation where the Laplacian is replaced by a sub-Laplacian (also called ``Hörmander sum of square''), which is an hypoelliptic operator. We handle the problem of describing the propagation of singularities in such equations : the main new phenomenon that we describe is that singularities can propagate along abnormal curves at any speed between $0$ and $1$. This general result extends an idea due to R. Melrose, and we then illustrate it on an example, the Martinet case, following a joint work with Y. Colin de Verdière. Our statements are part of a classical/quantum correspondance between sub-Riemannian geometry (on the classical side) and the hypoelliptic operator (on the quantum side), which is also helpful to interpret results in control theory and spectral theory of hypoelliptic operators.
| | | | Gestion: Maxime |
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| | Workshop Numerical Waves () | | | | | | | | | | | | Gestion: Maxime |
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| | Lise-Marie Imbert-Gérard (University of Arizona) | | | | | | | | | | | | Gestion: Maxime |
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| | Rachele Allena (LJAD) | | | | TBA | | | | | | | | Gestion: Florence |
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| | Antoine Cerfon (Courant Institute (New York)) | | | | Fast numerical schemes for the stepped pressure plasma model | | | | | | | | Gestion: Florence |
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| 16/12/2021 | | | | | | | | Salle de conférences | | |
| | Soutenance de l'HDR de Claire Scheid () | | | | | | | | | | |
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