Simulation of gravitational objects in Bose-Einstein condensates

Abstract

In this diplom-arbeit I consider a specific class of "analogue models" of curved spacetime that are specifically based on the use of Bose-Einstein condensates. As is usual in "analogue models", we are primarily interested in the kinematics of fields and quanta immersed in a curved-space background. We are not directly concerned with the Einstein equations of general relativity. Over the last few years numerous papers concerning "analogue models" have been published, the key result being that in many dynamical systems the perturbations have equations of motion that are governed by an "effective metric" that can often be interpreted in terms of an equivalent gravitational field. After a brief introduction concerning Bose-Einstein condensates and general relativity, I explain the connection between these two fields. Several specific examples are then explored in a little more detail: 1) Sinks and acoustic black holes [dumb holes]. 2) Ring-shaped Laval nozzles and acoustic horizons. 3) the de Sitter universe. In particular, the de Sitter universe is modelled by a freely expanding condensate obtained by suddenly switching off the trap that normally holds the condensate in place.