Dynamical flows through Dark Matter Haloes: Inner perturbative dynamics, secular evolution, and applications

Abstract

We investigate statistically the dynamical consequences of cosmological fluxes of matter and related moments on progenitors of today's dark matter haloes. Their dynamics is described via canonical perturbation theory which accounts for two types of perturbations: the tidal field corresponding to fly-bys and accretion of dark matter through the halo's outer boundary. he dynamical equations are solved linearly, order by order, projecting on a biorthogonal basis to consistently satisfy the field equation. Since our solution of the Boltzmann Poisson equations is explicit, it allows statistical predictions for the ensemble distribution of the inner dynamical features of haloes. The secular evolution of open galactic haloes is investigated: we derive the kinetic equation which governs the quasi-linear evolution of dark matter profile induced by infall and its corresponding gravitational correlations. This yields a Fokker Planck-like equation for the angle-averaged underlying distribution function. We show how these extensions to the classical theory could be used to (i) observationally constrain the statistical nature of the infall (ii) predict the observed distribution and correlations of substructures in upcoming surveys, (iii) predict the past evolution of the observed distribution of clumps, and finally (iv) weight the relative importance of the intrinsic (via the unperturbed distribution function) and external (tidal and/ or infall) influence of the environment in determining the fate of galaxies.