Quantum Origin of the Primordial Fluctuation Spectrum and its Statistics

Abstract

The account of the origin of cosmic structure, as provided by the standard inflationary paradigm, is not fully satisfactory, as has been argued in Perez et al 2006. The central point of that work is to point out the need to discuss and explore the physical mechanism that is capable of generating the inhomogeneity and anisotropy of our Universe, starting from an exactly homogeneous and isotropic initial state associated with the early inflationary regime. We review this issue briefly here together with the proposal to address this shortcoming in terms of a dynamical collapse of the vacuum state of the inflaton field. We also briefly indicate how this issues might be connected to other questions being faced in the study of the quantum/gravity interface, and their relevance to the investigations concerning the statistical characterization of the primordial spectrum.