Bubble Baryogenesis

I will discuss an alternative mechanism of baryogenesis in which a scalar baryon undergoes a percolating first-order phase transition in the early Universe. The potential barrier that divides the phases contains explicit B and CP violation and the corresponding instanton that mediates decay is therefore asymmetric. The nucleation and growth of these asymmetric bubbles dynamically generates baryons, which thermalize after percolation; bubble collision dynamics can also add to the asymmetry yield. I will present an explicit toy model that undergoes bubble baryogenesis, and discuss how to numerically study the evolution of the baryon asymmetry through bubble nucleation and growth, bubble collisions, and washout. More realistic constructions, in which the scalar baryon and its potential arise amongst the color-breaking minima of the MSSM, or in the supersymmetric neutrino seesaw mechanism, will also be proposed. Finally I will discuss phenomenological consequences, such as gravitational waves.