Résumé / Abstract Journal-club_Doctorants

Séminaire Doctorants / Seminar PhD students

« Secular resonant orbital diffusion and its WKB limit »

Jean-Baptiste Fouvry
Institut d'Astrophysique de Paris (Paris, France)

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.
mercredi 14 janvier 2015 - 17:00
Salle Entresol Daniel Chalonge, Institut d'Astrophysique
Page web du Séminaire / Seminar's webpage