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arXiv · 2207.00311

Numerical studies of back-reaction effects in an analog model of cosmological pre-heating

Salvatore Butera·Iacopo Carusotto
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Abstract

We theoretically propose an atomic Bose-Einstein condensate as an analog model of back-reaction effects during the pre-heating stage of early Universe. In particular, we address the out-of-equilibrium dynamics where the initially excited inflaton field decays by parametrically exciting the matter fields. We consider a two-dimensional, ring-shaped BEC under a tight transverse confinement whose transverse breathing mode and the Goldstone and dipole excitation branches simulate the inflaton and quantum matter fields, respectively. A strong excitation of the breathing mode leads to an exponentially-growing emission of dipole and Goldstone excitations via parametric pair creation: our numerical simulations of the BEC dynamics show how the associated back-reaction effect not only results in an effective friction of the breathing mode but also in a quick loss of longitudinal spatial coherence of the initially in-phase excitations. Implications of this result on the validity of the usual semiclassical description of back-reaction are finally discussed.

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Salvatore Butera, Iacopo Carusotto. 2022-07-01. Numerical studies of back-reaction effects in an analog model of cosmological pre-heating. https://doi.org/10.1103/physrevlett.130.241501

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