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T: Fachverband Teilchenphysik
T 22: Astroteilchenphysik und Kosmologie (Theorie)
T 22.5: Vortrag
Mittwoch, 30. März 2011, 17:45–18:00, 30.23: 3-1
Non-linear perturbations for Dark Matter — •Ninetta Saviano1, Gianpiero Mangano2, Massimo Pietroni3, and Matteo Viel4 — 1University of Hamburg, II institute for theoretical physics — 2INFN, Sezione di Napoli, Dipartimento di scienze fisiche di Napoli — 3INFN,sezione di Padova, — 4INAF Osservatorio Astronomico di Trieste
New generation galaxy surveys are measuring the statistical properties of the matter distribution with high precision, providing information about the dark side of the Universe. In this contest, a reliable comparison between theoretical models and observations requires going beyond the linear order in perturbation theory.
We propose a method to calculate the correlation functions for the density, velocity and pressure fields. We find that the correlation functions evolve in time according to a truncated system of integro-differential equations.
The starting point is constituted by the non-linear integro-differential Boltzmann equation which governs the time evolution of the Dark Matter particle phase space distribution. This equation is translated in a set of coupled equations for the moments of the distribution which has been truncated to the second order but including the stress tensor. Going in Fourier space, we obtain the time evolution for these fluctuation fields and so the Power Spectrum and Bispectrum.