scholarly journals PRIMORDIAL BLACK HOLE CONSTRAINTS FOR CURVATON MODELS WITH PREDICTED LARGE NON-GAUSSIANITY

2013 ◽  
Vol 22 (07) ◽  
pp. 1350034 ◽  
Author(s):  
E. V. BUGAEV ◽  
P. A. KLIMAI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Power Spectrum ◽  
Mass Spectra ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
Curvature Perturbation ◽  
Small Scales ◽  
Non Gaussian ◽  
Spectrum Amplitude

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.

scholarly journals Small-scale primordial fluctuations in the 21cm Dark Ages signal

2020 ◽  
Author(s):  
Philippa S Cole ◽  
Joseph Silk
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Power Spectrum ◽  
High Redshift ◽  
Power Spectra ◽  
Mass Range ◽  
Small Scale ◽  
Primordial Black Hole ◽  
Small Scales ◽  
Single Field

Abstract Primordial black hole production in the mass range 10 − 104 M⊙ is motivated respectively by interpretations of the LIGO/Virgo observations of binary black hole mergers and by their ability to seed intermediate black holes which would account for the presence of supermassive black holes at very high redshift. Their existence would imply a boost in the primordial power spectrum if they were produced by overdensities reentering the horizon and collapsing after single-field inflation. This, together with their associated Poisson fluctuations would cause a boost in the matter power spectrum on small scales. The extra power could become potentially observable in the 21cm power spectrum on scales around k ∼ 0.1 − 50 Mpc−1 with the new generation of filled low frequency interferometers. We explicitly include the contribution from primordial fluctuations in our prediction of the 21cm signal which has been previously neglected, by constructing primordial power spectra motivated by single-field models of inflation that would produce extra power on small scales. We find that depending on the mass and abundance of primordial black holes, it is important to include this contribution from the primordial fluctuations, so as not to underestimate the 21cm signal. Evidently our predictions of detectability, which lack any modelling of foregrounds, are unrealistic, but we hope that they will motivate improved cleaning algorithms that can enable us to access this intriguing corner of PBH-motivated parameter space.

scholarly journals The Merger Rate of Black Holes in a Primordial Black Hole Cluster

Physics ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 372-378
Author(s):  
Viktor D. Stasenko ◽  
Alexander A. Kirillov
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mass Spectrum ◽  
Star Clusters ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
Central Black Hole ◽  
Solar Mass ◽  
Merger Rate

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.

On Primordial Black Holes and secondary gravitational waves generated from inflation with solo/multi-bumpy potential

2021 ◽  
Author(s):  
Rui feng Zheng ◽  
Jia ming Shi ◽  
Taotao Qiu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Waves ◽  
Power Spectra ◽  
Small Scale ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
Slow Roll ◽  
Spherical Collapse ◽  
Scalar Perturbations

Abstract It is well known that primordial black hole (PBH) can be generated in inflation process of the early universe, especially when the inflaton field has some non-trivial features that could break the slow-roll condition. In this paper, we investigate a toy model of inflation with bumpy potential, which has one or several bumps. We found that potential with multi-bump can give rise to power spectra with multi peaks in small-scale region, which can in turn predict the generation of primordial black holes in various mass ranges. We also consider the two possibilities of PBH formation by spherical collapse and elliptical collapse. And discusses the scalar-induced gravitational waves (SIGWs) generated by the second-order scalar perturbations.

scholarly journals EVOLUTION OF PRIMORDIAL BLACK HOLE MASS SPECTRUM IN BRANS–DICKE THEORY

2013 ◽  
Vol 22 (05) ◽  
pp. 1350022 ◽  
Author(s):  
D. DWIVEDEE ◽  
B. NAYAK ◽  
L. P. SINGH
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mass Spectrum ◽  
Energy Density ◽  
Analytic Solutions ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
Black Hole Mass ◽  
Linear And Nonlinear ◽  
The Universe

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.

ACCRETION MECHANISMS ONTO PRIMORDIAL BLACK HOLES

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1249-1252
Author(s):  
D. C. GUARIENTO ◽  
J. E. HORVATH
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Energy ◽  
Perfect Fluid ◽  
Test Fluid ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
Accretion Model ◽  
Hawking Evaporation

We study the evolution of a primordial black hole (PBH) taking into account the presence of dark energy modeled by a general perfect fluid. In the specific case of a stationary non-self-gravitating test fluid, the competition between radiation accretion, Hawking evaporation and the accretion of such a fluid has been studied in detail. The evaporation of PBHs is quite modified at late times by these effects. We address further generalizations of this scenario to consider other types of fluids, and point out early developments of a nonstationary accretion model.

scholarly journals Evaporating primordial black holes in gamma ray and neutrino telescopes

2021 ◽  
Vol 2021 (12) ◽  
pp. 051
Author(s):  
Antonio Capanema ◽  
AmirFarzan Esmaeili ◽  
Arman Esmaili
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Neutrino Energy ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
Neutrino Telescopes ◽  
Time Profiles ◽  
Neutrino Fluxes

Abstract A primordial black hole in the last stages of evaporation and located in the local neighborhood can produce a detectable signal in gamma ray and neutrino telescopes. We re-evaluate the expected gamma ray and neutrino fluxes from these transient point events and discuss the consequences for existing constraints. For gamma rays we improve the current bounds by a factor of few, while for neutrinos we obtain significantly different results than the existing literature. The capability and advantages of neutrino telescopes in the search for primordial black holes is discussed thoroughly. The correlations of gamma ray and neutrino energy and time profiles will be promoted as a powerful tool in identifying the primordial black holes, in case of detection.

scholarly journals TIME EVOLUTION OF A NONSINGULAR PRIMORDIAL BLACK HOLE

2012 ◽  
Vol 21 (03) ◽  
pp. 1250027
Author(s):  
MANASSE R. MBONYE ◽  
NICHOLAS BATTISTA ◽  
BENJAMIN FARR
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Time Evolution ◽  
Evolutionary History ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
History Of ◽  
Early Radiation ◽  
The One ◽  
The Universe

There is growing notion that black holes may not contain curvature singularities (and that indeed nature in general may abhor such spacetime defects). This notion could have implications on our understanding of the evolution of primordial Black holes (PBHs) and possibly on their contribution to cosmic energy. This paper discusses the evolution of a nonsingular black hole (NSBH) based on a recent model [M. R. Mbonye and D. Kazanas, Phys. Rev. D. 72 (2005) 024016]. The model is used to discuss the time evolution of a primordial black hole (PBH), through the early radiation era of the universe to present, under the assumption that PBHs are nonsingular. In particular, we track the evolution of two benchmark PBHs, namely the one radiating up to the end of the cosmic radiation domination era, and the one stopping to radiate currently, and in each case determine some useful features including the initial mass mf and the corresponding time of formation tf. It is found that along the evolutionary history of the universe the distribution of PBH remnant masses (PBH-RM) PBH-RMs follows a power law. We believe such a result can be a useful step in a study to establish current abundance of PBH-MRs.

scholarly journals The minimum testable abundance of primordial black holes at future gravitational-wave detectors

2021 ◽  
Vol 2021 (11) ◽  
pp. 039
Author(s):  
Valerio De Luca ◽  
Gabriele Franciolini ◽  
Paolo Pani ◽  
Antonio Riotto
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Gravitational Wave ◽  
Primordial Black Hole ◽  
Spatial Distributions ◽  
Primordial Black Holes ◽  
Next Generation ◽  
Einstein Telescope ◽  
Gravitational Wave Detectors

Abstract The next generation of gravitational-wave experiments, such as Einstein Telescope, Cosmic Explorer and LISA, will test the primordial black hole scenario. We provide a forecast for the minimum testable value of the abundance of primordial black holes as a function of their masses for both the unclustered and clustered spatial distributions at formation. In particular, we show that these instruments may test abundances, relative to the dark matter, as low as 10-10.

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