School of Physics and Astronomy

Gravitational waves from the sound of a first order phase transition

20 November 2013

Time: 4:30pm
Venue: Maths 103

The London Relativity and Cosmology Seminar
David Weir (Helsinki)

We present the results of large-scale 3D simulations of first order phase transitions in the early universe. The fluid is included for the first time, allowing us to tune the wall velocity. The transition proceeds by the nucleation, growth, and collision of bubbles of the new phase in the coupled scalar field-fluid system. The resulting gravitational wave and fluid power spectra are calculated for a variety of detonations and deflagrations. Acoustic waves set up during the phase transition continue to be a source of gravitational waves long after the bubbles have merged.