Canonical description of cosmological backreaction

TL;DR

This paper develops canonical methods to incorporate quantum correlations into cosmological models, revealing how inhomogeneities can develop from vacuum states due to quantum non-locality and correlations.

Contribution

It introduces new models for quantum correlations in cosmology using canonical methods, extending beyond background approximations.

Findings

Conditions for inhomogeneity growth from vacuum

Quantum non-locality modeled as local theory with non-classical degrees

Evolution equations for perturbation moments

Abstract

Canonical methods of quasiclassical dynamics make it possible to go beyond a strict background approximation for cosmological perturbations by including independent fields such as correlation degrees of freedom. New models are introduced and analyzed here for cosmological dynamics in the presence of quantum correlations between background and perturbations, as well as cross-correlations between different modes of a quantum field. Evolution equations for moments of a perturbation state reveal conditions required for inhomogeneity to build up out of an initial vacuum. A crucial role is played by quantum non-locality, formulated by canonical methods as an equivalent local theory with non-classical degrees of freedom given by moments of a quantum state.