### (1) Presentation(s)

 Lun. 05/02/2018 13:30 Grande Ourse, Bâtiment 13, Etage 1Séminaire PENARRUBIA Jorge (Institute for Astronomy - Edinburgh Univ.) Finding the invisible - the search for dark substructures (LUPM/Interactions fondamentales, Astroparticules et Cosmologie) Sommaire: One of the most striking predictions from the Cold Dark Matter (CDM) paradigm postulates the existence of myriads of planet-sized subhaloes devoid of stars (i.e. dark'). A large population of these objects generates a stochastic gravitational field that can perturb the trajectories of visible systems. In this talk I will present a statistical technique for deriving the spectrum of random fluctuations directly from the number density of substructures with known mass and size functions.I will show that in galaxies like the Milky Way the fluctuations of the tidal field are completely dominated by the smallest and most abundant subhaloes. In light of this result I will discuss observational experiments that may be sufficiently sensitive to Galactic tidal fluctuations to probe the `dark'' low-end of the subhalo mass function and constrain the particle mass of warm and ultra-light axion dark matter models.Pour plus d'informations, merci de contacter Lavalle J.