MATTER FROM BLACK HOLES. “Baryogenesis is somehow linked with PBH formation and that the reason why the observed BAU is so small is due to the extreme rarity of the number of Hubble domains that collapse to form PBH, which is itself responsible for a late matter domination after equality.” (PBH = primordial black hole; BAU = baryon asymmetry).
https://royalsocietypublishing.org/doi/10.1098/rsta.2019.0091