Implications of primordial black holes on the first stars and the origin of the super--massive black holes

Understand

If the cosmological dark matter has a component made of small primordial black holes, they may have a significant impact on the physics of the first stars and on the subsequent formation of massive black holes.

• Primordial black holes would be adiabatically contracted into these stars and then would sink to the stellar center by dynamical friction, creating a larger black hole which may quickly swallow the whole star.
• If these primordial black holes are heavier than $\sim 10^{22} {\rm g}$, the first stars would likely live only for a very short time and would not contribute much to the reionization of the universe.
• They would instead become $10 - 10^3 M_\odot$ black holes which (depending on subsequent accretion) could serve as seeds for the super--massive black holes seen at high redshifts as well as those inside galaxies today.