A new approach to halo counting statistics: path-integral, non-spherical halo collapse and primordial non-Gaussianity
Pier Stefano Corasaniti
Observatoire de Paris Meudon
Wed, Oct. 12th 2011, 14:15
Salle Claude Itzykson, Bât. 774, Orme des Merisiers
The mass distribution of dark matter halos in the universe carries unique information on the non-linear gravitational processes that have shaped the late time phase of cosmic structure formation. Due to the complexity of the non-linear collapse of dark matter density fluctuations, the halo mass function has been mainly investigate using numerical N-body simulations. In this talk I will review some recent theoretical advancements based on a path-integral formulation of the Excursion Set theory. Using such a formalism I will present an analytical computation of the halo mass function for Gaussian and non-Gaussian initial conditions in the case of an effective stochastic barrier model which captures the main features of the non-spherical collapse of dark matter halos. This provides a mathematical description of halo mass function that explicitly depends on physically motivated model parameters and which we find to be in remarkable agreement with Gaussian and non-Gaussian numerical N-body simulation results.
Contact : ccaprini