Supercooled Cosmological Simulator

An important process in the very earliest stages of our universe, in our present understanding, is the formation of `bubbles': inside these bubbles matter exists in a new state. These bubbles nucleate spontaneously, grow through space, and merge with each other over time. It is even possible that the Big Bang corresponds to this sort of bubble nucleation event. These bubbles nucleate in a `supercooled' background: a background that is cold enough for bubbles to be able to spontaneously form. However, it is likely that although it is supercooled the background is still somewhat warm. The effects of this warm background are not well understood, and its effects may influence observable features of the universe today, such as the nature of primordial gravitational waves, for example.

An important recent breakthrough, facilitated by the development of quantum technologies, is that quantum systems of ultracold atoms with many analogous properties to the quantum fields relevant in the early universe can now be created in the lab, and hence function as a simulator of the early universe. One important effect that one could simulate with these analogue simulators is this type of bubble formation. In this research, we will explore, theoretically, the effects that having a warm background has on bubble nucleation, growth, and mergers in these analogue simulators. By better understanding these thermal effects theoretically we may be able to propose experiments that the simulators can carry out which will shed light on unresolved questions about the early universe itself.