Speaker
Mateusz Zych
(University of Warsaw)
Description
Terminal velocity of bubble walls in cosmological first-order phase transitions is a key parameter affecting both the primordial gravitational wave signal and baryon asymmetry production in electroweak baryogenesis. In this talk, I present recent results showing that, under local thermal equilibrium, pure hydrodynamic backreaction can lead to steady-state expansion, as confirmed by numerical simulations. However, this is not generic. Runaways are more common, as bubble walls often reach supersonic velocities before the fluid shell forms. To capture this effect, we extend analytical methods beyond local equilibrium and provide a criterion to identify physical detonations, with important consequences for cosmological observables.
Authors
Ignacy Nałęcz
(University of Warsaw)
Dr
Marek Lewicki
(University of Warsaw)
Mateusz Zych
(University of Warsaw)
Tomasz Krajewski
(Nicolaus Copernicus Astronomical Center)
