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arXiv · 2107.04342

Quantum fluctuations and semiclassicality in an inflaton-driven evolution

David Brizuela·Tomasz Pawlowski
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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: $(i)$ during inflation the universe rapidly spreads out in volume which leads to significant relative variance by the end of inflation; $(ii)$ despite that, the quantum evolution can still be described to high accuracy by semiclassical methods; $(iii)$ 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.

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David Brizuela, Tomasz Pawlowski. 2021-07-09. Quantum fluctuations and semiclassicality in an inflaton-driven evolution. https://doi.org/10.1088/1475-7516%2F2022%2F10%2F080

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