Primordial black holes as a probe of strongly first-order electroweak phase transition

Understand

Primordial black holes can be produced by density fluctuations generated from delayed vacuum decays of first-order phase transition.

• The primordial black holes generated at the electroweak phase transition have masses of about $10^{-5}$ solar mass.
• Such primordial black holes in the mass range can be tested by current and future microlensing observations, such as Subaru HSC, OGLE, PRIME and Roman telescope.
• Therefore, we may be able to explore new physics models with strongly first-order electroweak phase transition via primordial black holes.