Domain walls seeding the electroweak phase transition

Understand

Topological defects can act as local impurities that seed cosmological phase transitions.

• In this paper we study the case of domain walls, and how they can affect the electroweak phase transition in the Standard Model extended with a $Z_2$-odd scalar singlet.
• When the transition is two-step, the early breaking of the $Z_2$ symmetry implies the formation of domain walls which can then act as nucleation sites for the second step.
• We develop a method based on dimensional reduction to calculate the rate of the catalyzed phase transition within the 3d theory on the domain wall surface.