Showing papers by "Nicola Bartolo published in 2006"

Cosmic microwave background anisotropies at second order: I

Abstract: We present the computation of the full system of Boltzmann equations at second order describing the evolution of the photon, baryon and cold dark matter fluids. These equations allow one to follow the time evolution of the cosmic microwave background anisotropies at second order at all angular scales from the early epoch, when the cosmological perturbations were generated, to the present, through the recombination era. This paper sets the stage for the computation of the full second-order radiation transfer function at all scales and for a generic set of initial conditions specifying the level of primordial non-Gaussianity. In a companion paper, we will present the computation of the three-point correlation function at recombination which is very relevant for the issue of non-Gaussianity in the cosmic microwave background anisotropies.

CMB Anisotropies at Second Order I

Abstract: We present the computation of the full system of Boltzmann equations at second-order describing the evolution of the photon, baryon and cold dark matter fluids. These equations allow to follow the time evolution of the Cosmic Microwave Background (CMB) anisotropies at second-order at all angular scales from the early epoch, when the cosmological perturbations were generated, to the present through the recombination era. This paper sets the stage for the computation of the full second-order radiation transfer function at all scales and for a a generic set of initial conditions specifying the level of primordial non-Gaussianity. In a companion paper, we will present the computation of the three-point correlation function at recombination which is so relevant for the issue of non-Gaussianity in the CMB anisotropies.

The full second-order radiation transfer function for large-scale CMB anisotropies

Abstract: We calculate the full second-order radiation transfer function for cosmic microwave background anisotropies on large angular scales in a flat universe filled with matter and cosmological constant. It includes (i) the second-order generalization of the Sachs–Wolfe effect, and of (ii) both the early and late integrated Sachs–Wolfe effects, and (iii) the contribution of the second-order tensor modes, and is valid for a generic set of initial conditions specifying the level of primordial non-Gaussianity.