Constraints on Primordial Black Holes and Primeval Density Perturbations from the Epoch of Reionization
نویسنده
چکیده
We investigate the constraint on the abundance of primordial black holes (PBHs) and the spectral index n of primeval density perturbations given by the ionizing photon background at the epoch of reionization. Within the standard inflationary cosmogony, we show that the spectral index n of the power-law power spectrum of primeval density perturbations should be n <1.27. Since the universe is still optical thick at the reionization redshift z ∼ 6 8, this constraint is independent of the unknown parameter of reheating temperature of the inflation. The ionizing photon background from the PBHs can be well approximated by a power law spectrum J(ν) ∝ ν3, which is greatly different from those given by models of massive stars and quasars. Subject headings: cosmology: theory large-scale structure of universe
منابع مشابه
Cosmological Constraints from Primordial Black Holes
Primordial black holes may form in the early Universe, for example from the collapse of large amplitude density perturbations predicted in some inflationary models. Light black holes undergo Hawking evaporation, the energy injection from which is constrained both at the epoch of nucleosynthesis and at the present. The failure as yet to unambiguously detect primordial black holes places importan...
متن کاملSemianalytic Analysis of Primordial Black Hole Formation During a First-order QCD Phase Transition
It has recently been suggested that cosmologically significant numbers of black holes could form during a first-order QCD phase transition. Further, it has been asserted that these black holes would have masses corresponding naturally to the inferred mass (∼ 1M⊙) of the MACHOs responsible for the observed gravitational microlensing events. In this model, the underlying spectrum of primordial de...
متن کاملProbability Distribution of Primordial Angular Momentum and Formation of Massive Black Holes Hajime SUSA
We consider the joint probability distribution function for the mass contrast and angular momentum of over-density regions on the protogalactic scale and investigate the formation of massive black holes at redshift z > 10. We estimate the growth rate of the angular momentum by the linear perturbation theory and the decay rate by the Compton drag and apply the Press-Schechter theory to obtain th...
متن کاملBounds from Primordial Black Holes with a Near Critical Collapse Initial Mass Function
Recent numerical evidence suggests that a mass spectrum of primordial black holes (PBHs) is produced as a consequence of near critical gravitational collapse. Assuming that these holes formed from the initial density perturbations seeded by inflation, we calculate model independent upper bounds on the mass variance at the reheating temperature by requiring the mass density not exceed the critic...
متن کاملPrimordial black hole constraints in cosmologies with early matter domination
Moduli fields, a natural prediction of any supergravity and superstring-inspired supersymmetry theory, may lead to a prolonged period of matter domination in the early Universe. This can be observationally viable provided the moduli decay early enough to avoid harming nucleosynthesis. If primordial black holes form, they would be expected to do so before or during this matter dominated era. We ...
متن کامل