Inflation including collapse of the wave function: The quasi-de Sitter
  case
  The precise physical mechanism describing the emergence of the seeds of
cosmic structure from a perfect isotropic and homogeneous universe has not been
fully explained by the standard version of inflationary models. To handle this
shortcoming, D. Sudarsky and collaborators have developed a proposal: the
self-induced collapse hypothesis. In this scheme, the objective collapse of the
inflaton wave function is responsible for the emergence of inhomogeneity and
anisotropy at all scales. In previous papers, the proposal was developed with
an almost exact de Sitter space-time approximation for the background that led
to a perfect scale-invariant power spectrum. In the present article, we
consider a full quasi-de Sitter expansion and calculate the primordial power
spectrum for three different choices of the self-induced collapse. The
consideration of a quasi-de Sitter background allow us to distinguish
departures from an exact scale-invariant power spectrum that are due to the
inclusion of the collapse hypothesis. These deviations are also different from
the prediction of standard inflationary models with running spectral index.
Comparison with the primordial power spectrum and the CMB temperature
fluctuation spectrum preferred by the latest observational data is also
discussed. From the analysis performed in this work, it follows that most of
the collapse schemes analysed in this paper are viable candidates to explain
present observations of the CMB fluctuation spectrum.
