Strong First Order EWPT and Strong Gravitational Waves in $Z_3$-symmetric Singlet Scalar Extension

Understand

The nature of electroweak (EW) phase transition (PT) is of great importance.

• It may give a clue to the origin of baryon asymmetry if EWPT is strong first order.
• Although it is second order within the standard model (SM), a great many extensions of the SM are capable of altering the nature.
• Thus, gravitational wave (GW), which is supposed to be relics of strong first order PT, is a good complementary probe to new physics beyond SM (BSM).