Speaker
Description
Many extensions of the Standard Model of particle physics predict that one or more phase transitions took place in the early universe. Such phase transitions involve the nucleation, expansion, and collision of bubbles of the new phase. These collisions (and associated interactions of sound waves in the plasma) are substantial, potentially detectable, sources of gravitational waves. As a result, they can act as a probe of particle physics beyond the Standard Model. Excellent progress has been made in developing high-level modelling of the gravitational wave power spectrum from early universe phase transitions. This progress has been made possible in part by large-scale simulations of bubble collisions. However, challenges remain, particularly in understanding and modelling the development of nonlinearities, including shocks and turbulence. These become increasingly important for strong phase transitions. I will discuss features of the underlying particle physics models, as well as the latest simulation results. I will explain how the results can inform theoretical understanding and future analytical models of the resulting gravitational wave power spectra.
