It was recently shown that a large value of the tensor to scalar ratio r implies a constraint on the minimum value of the sound speed c(s) of primordial curvature perturbations during inflation that is stronger than current ...

We study the realization of slow-roll inflation in N = 1 supergravities where inflation is the result of the evolution of a single chiral field. When there is only one flat direction in field space, it is possible to derive ...

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 ...

We investigate the cosmology of the vacuum energy decaying into cold dark matter according to thermodynamics description of Alcaniz & Lima. We apply this model to analyze the evolution of primordial density perturbations ...

Future cosmic microwave background polarization experiments will search for evidence of primordial tensor modes at large angular scales, in the multipole range 4≤≤50. Because in that range there is some mild evidence of ...

We develop a non-perturbative formalism for scalar metric fluctuations from a 5D extended version of General Relativity in vacuum. In this work we concentrate our efforts on calculations valid on large cosmological ...

In this thesis, we show how future cosmological observations can provide us access to unveil the mechanism responsible for the origin of the structure in our universe. The primordial perturbations sourced by quantum vacuum ...