Droplet collapse during strongly supercooled transitions

We simulate the decay of isolated, spherically symmetric droplets in a cosmological phase transition. It has long been posited that such heated droplets of the metastable state could form, and they have recently been observed in 3D multibubble simulations. In those simulations, the droplets were associated with a reduction in the wall velocity and a decrease in the kinetic energy of the fluid, with a consequent suppression in the gravitational wave power spectrum. In the present work, we track the wall speed and kinetic energy production in isolated droplets and compare them to those found in multibubble collisions. The late-time wall velocities that we observe match those of the 3D simulations, though we find that the spherical simulations are a poor predictor of the kinetic energy production. This implies that spherically symmetric simulations could be used to refine baryogenesis predictions due to the formation of droplets, but not to estimate any accompanying suppression of the gravitational wave signal.

Automated summary

This study simulated the decay of isolated droplets in a cosmological phase transition and compared the wall speed and kinetic energy production in isolated droplets to those found in multibubble collisions. It suggests that spherically symmetric simulations could refine predictions of baryogenesis due to the formation of droplets, but not estimate any accompanying suppression of the gravitational wave signal.