The response of stellar discs to perturbations

The aim of this project is to understand the dynamics of stellar discs -- including that of our own Galaxy -- using dynamical modelling applied to data from Gaia and similar surveys.

The starting point for understanding the dynamical structure of self-gravitating stellar discs is usually the construction of an axisymmetrized equilibrium model. Real stellar discs are never axisymmetric though and so the next step is to apply the methods of perturbation theory to calculate both the qualitative and quantitative response of such models to the various types of noise experienced by real discs. Most investigations to date have focused on the frequency-dependent response of the disc, but this project adopts an explicitly time-dependent approach, which also makes comparison with N-body models more straightforward. We have recently built machinery for modelling the non-resonant dynamics of 2d discs and the objectives of the project are to extend this to handle orbital resonances and to vertical structure.