Bubble Wall Velocity from Holography

Understand

Cosmological phase transitions proceed via the nucleation of bubbles that subsequently expand and collide.

• The resulting gravitational wave spectrum depends 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 a strongly coupled, non-Abelian, four-dimensional gauge theory.