STAGE Secular relaxation of 1D self-gravitating systems

Date de mise à jour de l’offre

CNRS - Institut d'Astrophysique de Paris :

Unité Mixte de Recherche CNRS-Sorbonne Université

Description de la mission

Gravity is a long-range interaction. As such, stellar systems all share some fundamental similarities: (i) they are inhomogeneous, i.e. stars follow intricate orbits; (ii) they are self-gravitating, i.e. stars evolve in the gravitational potential that they self-consistently define, allowing the system to amplify perturbations; (iii) they are resonant, i.e. orbits introduce orbital frequencies, which naturally separate the dynamical timescale with the long timescale of orbital relaxation.
One-dimensional self-gravitating systems (also called self-gravitating sheets) offer then an ideal and tunable testbed to understand the long-term signatures of these essential dynamical specificities.

Upshot

This internship will be focused on describing the long-term resonant relaxation of 1D self-gravitating systems. We will first develop an efficient numerical code to integrate the dynamics of that system.
We will subsequently construct suitable quasi-stationary equilibrium solutions, in particular through Eddington inversion and angle-action coordinates. Once these elements set up, we will be in a position to perform the linear response theory of that system, i.e. characterise the efficiency with which this system can amplify perturbations. Finally, we will derive the appropriate Balescu-Lenard kinetic equation to describe the long-term orbital reshufflings undergone by the systems, while comparing these predictions with our own measurements from numerical simulations. All in all, these investigations will offer new clues on the intricate dynamics of long-range interacting systems, highlighting in particular the efficiency with which these systems can or cannot reach their thermodynamical equilibria.

Plus d'informations
http://www.secular-evolution.org/index.php?n=Site.MasterAstronomyInternship2021

Profil recherché

Modélisation

Niveau de qualification requis

Bac + 4/5 et +
  • Employeur
    CNRS - Institut d'Astrophysique de Paris
  • Secteur d’activité de la structure
    Enseignement - Formation - Recherche
  • Effectif de la structure
    De 51 à 250 salariés
  • Site internet de la structure
    http://www.iap.fr
  • Type de stage ou contrat
    Stage pour lycéens et étudiants en formation initiale
  • Date prévisionnelle de démarrage
  • Durée du stage ou contrat
    Plus de 4 mois et jusqu'à 6 mois
  • Le stage est-il rémunéré ?
    Oui
  • Niveau de qualification requis

    Bac + 4/5 et +
  • Lieu du stage
    CNRS - Insttitut d'Astrophysique de Paris
    98 bis Boulevard Arago
    75014 PARIS 14E ARRONDISSEMENT
  • Accès et transports
    RER, métro Denfert-Rochereau