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 decoherence induced by a time-dependent environment of deep subhorizon tensorial modes (i.e. primordial gravitational waves) through the trilinear interactions predicted by General Relativity. We first prove that a time dependent subhorizon environment of gravitational waves can be relevant for decoherence during inflation, by considering derivativeless interactions, which, in our case, give the most important results. Our results show that important non-Markovian effects pop up, instead, when dealing with derivative interactions. 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, which is a general property of quantum master equations.
