Séminaire Doctoral / Seminar PhD |
| « Secular resonant orbital diffusion and its WKB limit » |
|
Jean-Baptiste Fouvry |
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Stellar disks are non trivial dynamical systems, since they are both
dynamically relaxed, self-gravitating and perturbed by their environnement. Secular dynamics aims at studying the long-term evolution of such systems. During my presentation, I will first introduce some key tools of galactic dynamics (Boltzmann equation, angle-action coordinates and timescale separation), and present the secular diffusion equation, which describes the secular evolution of perturbed self-gravitating collisionless systems. The next step will be to apply this formalism to the case of 2D tepid disks in the WKB limit (i.e. where only tightly wound transient spirals are sustained by the disk.), and see how this limit allow us to recover some qualitative features from numerical experiments. If there is time, I will finally focus on the case of collisional systems and present the kinetic Lenard-Balescu equation along with its associated WKB limit. |
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mercredi 14 janvier 2015 - 17:00 Salle Entresol Daniel Chalonge, Institut d'Astrophysique |
| Page web du séminaire / Seminar's webpage |