Séminaire Doctorants / Seminar PhD students |
| « From particles to galaxies: fluctuations, collisions and large deviations » |
|
Anwar El Rhirhayi |
| The long-term evolution of galaxies and stellar systems relies on collective interactions that, although tiny at the individual scale, produce significant macroscopic effects. In this presentation, we will begin by introducing the Landau equation, which describes the average evolution of the velocity distribution under the effect of grazing and frequent collisions. To make these dynamics more tangible, we will illustrate it through a stochastic formulation inspired by Langevin, allowing for the direct simulation of collective noise. Finally, we will address the issue of atypical fluctuations via the principle of large deviations, which allows quantifying the occurrence of rare and potentially structuring events in the evolution of galactic systems. |
|
vendredi 13 février 2026 - 16:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique |
| Page web du Séminaire / Seminar's webpage |