Non-Gaussian Dark Matter perturbations and their imprint on the microwave background

Abstract

The phases of the Fourier transform of any linear cosmological perturbation may be random (the Gaussian case) or not (the non-Gaussian case). If a non-Gaussian inhomogeneity was generated during the inflationary era by some process of very high energy physics, its evolution may be computed using the usual linear theory. I focus on the perturbations induced on the microwave background (CMB) by an underlying non-Gaussian distribution of dark matter (DM). Giving the specific example of an inflationary bubble, I show how non-Gaussian structures lying on the last scattering surface (LSS) may give rise to ordered patterns in the CMB anisotropy field. The next high resolution observations of the CMB sky may eventually detect these signals.