Parametric Amplification of Gravitational Fluctuations during Reheating

Parametric Amplification of Gravitational Fluctuations During Reheating

We demonstrate that cosmological perturbations can undergo amplification by parametric resonance during the preheating period following inflation, even on scales larger than the Hubble radius, without violating causality. A unified description of gravitational and matter fluctuations is crucial in order to determine the strength of the instability. To extract specific signatures of the oscillat...

Parametric Amplification of Metric Fluctuations During Reheating in Two Field Models

It was recently suggested [1] that parametric resonance during the reheating phase of an inflationary Universe [2–4] may lead to an exponential amplification of superHubble scale gravitational fluctuations. If true, this would affect the usual predictions of inflationary models for observables such as the matter power spectrum and the spectrum of cosmic microwave anisotropies. In particular, it...

Parametric amplification of metric fluctuations through a bouncing phase

We clarify the properties of the behavior of classical cosmological perturbations when the Universe experiences a bounce. This is done in the simplest possible case for which gravity is described by general relativity and the matter content has a single component, namely a scalar field in a closed geometry. We show in particular that the spectrum of scalar perturbations can be affected by the b...

Baryogenesis from the amplification of vacuum fluctuations during inflation

We propose that the baryon asymmetry of the Universe may originate from the amplification of quantum fluctuations of a light complex scalar field during inflation. CP-violation is sourced by complex mass terms, which are smaller than the Hubble rate, as well as non-standard kinetic terms. We find that, when assuming 60 e-folds of inflation, an asymmetry in accordance with observation can result...

Parametric Amplification of Atoms