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.

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.

scholarly journals GW200105 and GW200115 are compatible with a scenario of primordial black hole binary coalescences

2022 ◽  
Vol 82 (1) ◽  
Author(s):  
Sai Wang ◽  
Zhi-Chao Zhao
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Cold Dark Matter ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
Microwave Background ◽  
Black Hole Binaries ◽  
Upper Limits ◽  
Merger Rate ◽  
The One

AbstractTwo gravitational wave events, i.e. GW200105 and GW200115, were observed by the Advanced LIGO and Virgo detectors recently. In this work, we show that they can be explained by a scenario of primordial black hole binaries that are formed in the early Universe. The merger rate predicted by such a scenario could be consistent with the one estimated from LIGO and Virgo, even if primordial black holes constitute a fraction of cold dark matter. The required abundance of primordial black holes is compatible with the existing upper limits from microlensing, caustic crossing and cosmic microwave background observations.

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 Monte Carlo Simulations of the 2+1 Dimensional Fokker-Planck Equation: Spherical Star Clusters Containing Massive, Central Black Holes

1985 ◽  
Vol 113 ◽  
pp. 373-413 ◽  
Author(s):  
Stuart L. Shapiro
Keyword(s):  
Black Holes ◽  
Monte Carlo ◽  
Black Hole ◽  
Phase Space ◽  
Star Clusters ◽  
Galactic Nuclei ◽  
Planck Equation ◽  
Time Dependent ◽  
Central Black Hole ◽  
Fokker Planck Equation

The dynamical behavior of a relaxed star cluster containing a massive, central black hole poses a challenging problem for the theorist and intriguing possibilities for the observer. The historical development of the subject is sketched and the salient features of the physical solution and its observational consequences are summarized.The full dynamical problem of a relaxed, self-gravitating, large N-body system containing a massive central black hole has all the necessary ingredients to excite the most dispassionate many-body, computational physicist: it is a time-dependent, multidimensional, nonlinear problem which must be solved over widely disparate length and time scales simultaneously. The problem has been tackled at various levels of approximation over the years. A new 2+1 dimensional Monte Carlo simulation code has been developed in appreciable generality to solve the time-dependent Fokker-Planck equation in E-J space for this problem. The code incorporates such features as (1) a particle “cloning and renormalization” scheme to provide a statistically reliable population of test particles in low density regions of phase space and (2) a time-step “adjustment” algorithm to ensure integration on local relaxation timescales without having to follow typical particles on orbital trajectories. However, critical regions in phase space (e.g. disruption “loss-cone” trajectories) can still be followed on orbital timescales. Numerical results obtained with this Monte Carlo scheme for the dynamical structure and evolution of globular star clusters and dense galactic nuclei containing massive black holes are reviewed.Recent dynamical integrations of the Einstein field equations for spherical, collisionless (Vlasov) systems in General Relativity suggest a possible origin for the supermassive black holes believed to power quasars and active galactic nuclei. This scenario is discussed briefly.

scholarly journals Black Component of Dark Matter

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
A. V. Grobov ◽  
S. G. Rubin ◽  
V. Yu. Shalamova
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Mass Spectrum ◽  
Energy Density ◽  
Extra Dimensions ◽  
Primordial Black Hole ◽  
Hole Formation ◽  
Specific Mass ◽  
Black Hole Formation

A mechanism of primordial black hole formation with specific mass spectrum is discussed. It is shown that these black holes could contribute to the energy density of dark matter. Our approach is elaborated in the framework of universal extra dimensions.

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 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 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.

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