INSTABILITY AND SUBSEQUENT EVOLUTION OF ELECTROWEAK BUBBLES

Bubbles in a first-order electroweak phase transition are nucleated with radii R0 and expand with velocity v. If v is subsonic, a bubble becomes unstable to nonspherical perturbations when its radius is roughly 10(4)R0. These perturbations accelerate the transition, and the effective velocity of bubble growth rapidly becomes supersonic. The transition should subsequently proceed spherically via detonation. If for some reason the onset of detonation is postponed, the surface area of the bubbles may be enhanced by 10(5). We discuss consequences for electroweak baryogenesis.