HOLOTUBE: Bubble Dynamics from Holography

 Cosmological phase transitions proceed via the nucleation of bubbles that subsequently expand and collide. The resulting gravitational waves depend crucially on the bubble wall velocity. Microscopic calculations of this velocity are challenging even in weakly coupled theories. We use holography to compute the wall velocity from first principles in several strongly coupled, non-Abelian, four-dimensional gauge theories. We find that the velocity and the profile of the wall are completely determined dynamically in terms of the nucleation temperature. We investigate the applicability of hydrodynamics to this system.