A common origin for baryons and dark matter

Understand

The origin of the baryon asymmetry of the Universe (BAU) and the nature of dark matter are two of the most challenging problems in cosmology.

• We propose a scenario in which the gravitational collapse of large inhomogeneities at the quark-hadron epoch generates both the baryon asymmetry and dark matter in the form of primordial black holes (PBHs).
• This is due to the sudden drop in radiation pressure during the transition from a quark-gluon plasma to non-relativistic hadrons.
• The collapse to a PBH is induced by fluctuations of a light spectator scalar field in rare regions and is accompanied by the violent expulsion of surrounding material, which might be regarded as a sort of "primordial supernova" .