Primordial black hole formation by vacuum bubbles II

Understand

The discoveries of LIGO/Virgo black holes in recent years have revitalized the study of primordial black holes.

• In this work, we investigate a mechanism where primordial black holes are formed by vacuum bubbles that randomly nucleate during inflation through quantum tunneling.
• After inflation, these bubbles typically run into the ambient radiation fluid with a large Lorentz factor.
• In our previous work, we assumed the bubble fields are strongly coupled to the standard model particles so that the bubble wall is impermeable.