Primordial Black Holes as Dark Matter: the Power Spectrum and Evaporation of Early Structures

We consider the possibility that massive primordial black holes are the dominant form of dark matter. Black hole formation generates entropy fluctuations that adds a Poisson noise to the matter power spectrum. We use Ly-α forest observations to constrain this Poisson term in matter power spectrum, then we constrain the mass of black holes to be less than ∼ few × 10 M⊙. We also find that structures with less than ∼ 10 primordial black holes evaporate by now. Subject headings: Cosmology: theory — dark matter — black hole physics — large-scale structure of universe — cosmology: observations — quasars: absorption lines