Seminar

Stochastic dynamics and the nature of Dark Matter

By
Jorge Peñarrubia (The Royal Observatory)
Date
Place
Zoom
seminar ICCUB
Current spectroscopic and astrometric surveys of the Milky Way are revolutionazing our understanding of stellar motions in our Galaxy. A key question is how to use this information to (i) infer the distribution of Dark Matter (DM) in the Milky Way and (ii) test its particle nature. Both goals pose important challenges. First, I will show evidence for strong perturbations in both the Milky Way disc and stellar halo which are likely induced by the recent accretion of the Large Magellanic Clouds, and could bias previous measurements of the Galactic potential that rely on equilibrium assumptions.
Second, I will discuss how the the presence of dark substructures in the Milky Way halo induces random fluctuations in the local tidal field, and outline future dynamical experiments that could measure the clumpiness of dark matter on ~pc scales, thus providing an observational window to test whether DM is made of particles or Primordial Black Holes. For illustration, I will present Monte-Carlo N-body experiments that follow the evolution of stellar binaries with extreme separations and protoplanetary discs in a clumpy potential and discuss follow-up work.