|Speaker:||Jorinde van de Vis (Utrecht University)|
|Title:||Gravitational waves from first order phase transitions: Using LISA to probe particle physics|
|Date (JST):||Fri, Dec 02, 2022, 14:00 - 15:30|
In many extensions of the Standard Model, the electroweak phase transition is first order. Such a phase transition proceeds via the formation and collision of bubbles. The bubble collisions can source a stochastic gravitational wave background signal, with characteristic frequency right in the sensitivity band of LISA. We can thus use data from gravitational wave experiments to probe physics beyond the standard model.
In this talk, I will focus on the contribution to the gravitational wave signal from sound waves that get formed in the interactions between the plasma and the bubble walls. I will discuss the parameters that describe the phase transition, and argue that the speed of sound plays a significant role. To quantify the importance of this effect, I will discuss an accurate computation of the sound speed in a representative model. I will then discuss the amount of information that can be extracted if LISA would measure a stochastic gravitational wave signal.
I will end by demonstrating how the gravitational wave spectrum can be affected by primordial density perturbations, and briefly discuss the effects for observability.