Modelling the Galactic disc in the era of Gaia
There are broadly two approaches to Milky Way dynamical modelling: the top-down approach, consisting in carrying out hydrodynamical simulations of Milky Way-like galaxies in a cosmological context, and the bottom-up approach, which consists in building a dynamically coherent model of the stellar component directly from data, by means of a phase-space distribution function obeying the collisionless Boltzmann equation. These two approaches are definitely complementary, but the second types of models still often rely on the assumptions of a smooth time-independent and axisymmetric gravitational potential, while Gaia data have revealed a very tumultuous and perturbed Milky Way disc. I will describe our work on perturbed models taking into account the effects of one main perturber, such as the Galactic bar, on the stellar distribution function of the Milky Way disc, and will outline our research program to later combine multiple perturbers as well as include the more complicated treatment of vertical oscillations of the disc as a response to external perturbers.