Speaker
Description
In order to shed light on the quantum-to-classical transition of the primordial
perturbations in single field inflation, we investigate the decoherence and associated quantum corrections to the correlation functions of large-scale (superhorizon) scalar curvature perturbations.
The latter are considered as an open quantum system which undergoes quantum decoherence induced by a time-dependent environment of deep subhorizon tensorial modes through the trilinear interactions predicted by General Relativity.
We first prove that, in full generality, a time dependent subhorizon environment can be relevant for decoherence during inflation, by considering derivativeless interactions, which, in our case, give the most important results. For the first time, the time dependence of the environment is properly taken into account by modifying the quantum master equation.
Important non-Markovian effects pop up, instead, when dealing with derivative interactions. Our results show that when considering the interplay between derivativeless and derivative interactions, decoherence is slowed down. This underlines the importance of accounting for all the interactions in open quantum-system calculations in an inflationary setting.
We finally compute the quantum corrections to cosmological correlation functions. We observe a resummation of the quantum corrections to the power spectrum, which is a
general property of quantum master equations. We extend these results to the bispectrum,
showing a decay of this correlation function in time which is analogous to the one found,
previously, for the power-spectrum.
