Analogue model of a FRW universe in Bose-Einstein condensates: Application of the classical field method

TL;DR

This paper models a Friedmann-Robertson-Walker universe analogue using Bose-Einstein condensates, employing the classical field method to simulate cosmological particle creation and analyze effects of modified dispersion relations.

Contribution

It introduces a numerical simulation approach of cosmological phenomena in Bose-Einstein condensates using the classical field method with the truncated Wigner approximation.

Findings

Particle production matches theoretical predictions at long wavelengths.

Modified dispersion relations influence particle creation.

The classical field method effectively models cosmological analogue phenomena.

Abstract

Analogue models of gravity have been motivated by the possibility of investigating phenomena not readily accessible in their cosmological counterparts. In this paper, we investigate the analogue of cosmological particle creation in a Friedmann-Robertson-Walker universe by numerically simulating a Bose-Einstein condensate with a time-dependent scattering length. In particular, we focus on a two-dimensional homogeneous condensate using the classical field method via the truncated Wigner approximation. We show that for various forms of the scaling function the particle production is consistent with the underlying theory in the long wavelength limit. In this context, we further discuss the implications of modified dispersion relations that arise from the microscopic theory of a weakly interacting Bose gas.