scholarly journals On Mass Spectra of Primordial Black Holes

Author(s):  
Alexander A. Kirillov ◽  
Sergey G. Rubin

Evidence for the primordial black holes (PBH) presence in the early Universe renews permanently. New limits on their mass spectrum challenge existing models of PBH formation. One of the known models is based on the closed walls collapse after the inflationary epoch. Its intrinsic feature is the multiple production of small mass PBH which might contradict observations in the nearest future. We show that the mechanism of walls collapse can be applied to produce substantially different PBH mass spectra if one takes into account the classical motion of scalar fields together with their quantum fluctuations at the inflationary stage. Analytical formulas have been developed that contain both quantum and classical contributions.

Physics ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 372-378
Author(s):  
Viktor D. Stasenko ◽  
Alexander A. Kirillov

In this paper, the merger rate of black holes in a cluster of primordial black holes (PBHs) is investigated. The clusters have characteristics close to those of typical globular star clusters. A cluster that has a wide mass spectrum ranging from 10−2 to 10M⊙ (Solar mass) and contains a massive central black hole of the mass M•=103M⊙ is considered. It is shown that in the process of the evolution of cluster, the merger rate changed significantly, and by now, the PBH clusters have passed the stage of active merging of the black holes inside them.


Astrophysics ◽  
1982 ◽  
Vol 18 (2) ◽  
pp. 192-199
Author(s):  
N. A. Zabotin ◽  
P. D. Nasel'skii

1980 ◽  
Vol 58 (4) ◽  
pp. 463-471
Author(s):  
Meiun Shintani

Considering the commutators between a scalar field and a conserved current, we shall clarify the connection between the mass spectrum for a scalar field and the structures of a current. For a special form of currents involving c-number functions, non-invariance of the vacuum under the corresponding transformation entails the existence of a massive mode. It is shown that once a type of currents is specified, the pole structures for [Formula: see text] depend only on c-number parts of Jμ(x). We shall show that the non-vanishing Goldstone commutator does not automatically imply the degeneracy of the vacuum state, and discuss the applicability of the Goldstone theorem.


2013 ◽  
Vol 22 (05) ◽  
pp. 1350022 ◽  
Author(s):  
D. DWIVEDEE ◽  
B. NAYAK ◽  
L. P. SINGH

We investigate the evolution of primordial black hole mass spectrum by including both accretion of radiation and Hawking evaporation within Brans–Dicke (BD) cosmology in radiation-, matter- and vacuum-dominated eras. We also consider the effect of evaporation of primordial black holes on the expansion dynamics of the universe. The analytic solutions describing the energy density of the black holes in equilibrium with radiation are presented. We demonstrate that these solutions act as attractors for the system ensuring stability for both linear and nonlinear situations. We show, however, that inclusion of accretion of radiation delays the onset of this equilibrium in all radiation-, matter- and vacuum-dominated eras.


2020 ◽  
Vol 496 (1) ◽  
pp. 60-66
Author(s):  
J L G Sobrinho ◽  
P Augusto

ABSTRACT Primordial black holes (PBHs) might have formed in the early Universe due to the collapse of density fluctuations. PBHs may act as the sources for some of the gravitational waves recently observed. We explored the formation scenarios of PBHs of stellar mass, taking into account the possible influence of the QCD phase transition, for which we considered three different models: crossover model, bag model, and lattice fit model. For the fluctuations, we considered a running-tilt power-law spectrum; when these cross the ∼10−9–10−1 s Universe horizon they originate 0.05–500 M⊙ PBHs that could (i) provide a population of stellar mass PBHs similar to the ones present on the binaries associated with all-known gravitational wave sources and (ii) constitute a broad-mass spectrum accounting for ${\sim}76{{\ \rm per\ cent}}$ of all cold dark matter in the Universe.


2013 ◽  
Vol 22 (07) ◽  
pp. 1350034 ◽  
Author(s):  
E. V. BUGAEV ◽  
P. A. KLIMAI

We consider the early Universe scenario which allows for production of non-Gaussian curvature perturbations at small scales. We study the peculiarities of a formation of primordial black holes (PBHs) connected with the non-Gaussianity. In particular, we show that PBH constraints on the values of curvature perturbation power spectrum amplitude are strongly dependent on the shape of perturbations and can significantly (by two orders of magnitude) deviate from the usual Gaussian limit [Formula: see text]. We give examples of PBH mass spectra calculations and PBH constraints for the particular case of the curvaton model.


Sign in / Sign up

Export Citation Format

Share Document