Inflationary Dynamics and Particle Production in a Toroidal Bose-Einstein Condensate

TL;DR

This paper theoretically investigates how a toroidal Bose-Einstein condensate can simulate inflationary universe dynamics, demonstrating phonon redshift, damping, and spontaneous particle creation observable through density correlations.

Contribution

It introduces a model for BEC-based analogue inflation, analyzing phonon behavior and particle creation during rapid expansion, linking condensed matter physics with cosmological inflation theories.

Findings

Phonons undergo redshift and damping during expansion.

Rapid expansion leads to spontaneous particle creation.

Particle creation can be detected via density correlations.

Abstract

We present a theoretical study of the dynamics of a Bose-Einstein condensate (BEC) trapped inside an expanding toroid that can realize an analogue inflationary universe. As the system expands, we find that phonons in the BEC undergo redshift and damping due to quantum pressure effects, owing to the thinness of the ring. We predict that rapidly expanding toroidal BEC's can exhibit spontaneous particle creation, and study this phenomenon in the context of an initial coherent state wavefunction. We show how particle creation would be revealed in the atom density and density correlations, and discuss connections to the cosmological theory of inflation.