Quantum fluctuations and semiclassicality in an inflaton-driven evolution
arXiv:2107.04342 · doi:10.1088/1475-7516/2022/10/080
Abstract
A semiclassical description of quantum systems is applied to probe the dynamics of the cosmological model of an inflationary universe with quadratic inflaton potential, described in a quantum framework of geometrodynamics. The systematic analysis, focusing in particular on the inflationary and post-inflationary epochs, revealed several surprising and counterintuitive features: during inflation the universe rapidly spreads out in volume which leads to significant relative variance by the end of inflation; despite that, the quantum evolution can still be described to high accuracy by semiclassical methods; moreover, in the post-inflationary epoch, as the order of included quantum corrections increases, the quantum trajectory approaches the classical one and the description involving second-order corrections only is actually the least accurate there. The consequence of the latter is that the effects of the quantum variances are washed out by the higher-order quantum corrections.
arXiv commentExpanded version of the paper accepted for publication in JCAP. We have included a more detailed derivation of the model, some clarifications on the presentation of the results, and several new references
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