scholarly journals Stellar mass primordial black holes as cold dark matter

2020 ◽  
Vol 496 (1) ◽  
pp. 60-66
Author(s):  
J L G Sobrinho ◽  
P Augusto
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Dark Matter ◽  
Mass Spectrum ◽  
Cold Dark Matter ◽  
Stellar Mass ◽  
Density Fluctuations ◽  
Primordial Black Holes ◽  
Qcd Phase Transition ◽  
The Universe

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.

scholarly journals Primordial black holes and the origin of the matter–antimatter asymmetry

2019 ◽  
Vol 377 (2161) ◽  
pp. 20190091 ◽  
Author(s):  
Juan García-Bellido
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Cold Dark Matter ◽  
Hot Spot ◽  
Large Mass ◽  
New Physics ◽  
Primordial Black Holes ◽  
Far From Equilibrium ◽  
The Universe

We review here a new scenario of hot spot electroweak baryogenesis where the local energy released in the gravitational collapse to form primordial black holes (PBHs) at the quark-hadron (QCD) epoch drives over-the-barrier sphaleron transitions in a far from equilibrium environment with just the standard model CP violation. Baryons are efficiently produced in relativistic collisions around the black holes and soon redistribute to the rest of the universe, generating the observed matter–antimatter asymmetry well before primordial nucleosynthesis. Therefore, in this scenario there is a common origin of both the dark matter to baryon ratio and the photon to baryon ratio. Moreover, the sudden drop in radiation pressure of relativistic matter at H 0 / W ± / Z 0 decoupling, the QCD transition and e + e − annihilation enhances the probability of PBH formation, inducing a multi-modal broad mass distribution with characteristic peaks at 10 −6 , 1, 30 and 10 6   M ⊙ , rapidly falling at smaller and larger masses, which may explain the LIGO–Virgo black hole mergers as well as the OGLE-GAIA microlensing events, while constituting all of the cold dark matter today. We predict the future detection of binary black hole (BBH) mergers in LIGO with masses between 1 and 5  M ⊙ , as well as above 80  M ⊙ , with very large mass ratios. Next generation gravitational wave and microlensing experiments will be able to test this scenario thoroughly. This article is part of a discussion meeting issue ‘Topological avatars of new physics’.

scholarly journals Primordial black holes from the QCD epoch: linking dark matter, baryogenesis, and anthropic selection

2020 ◽  
Vol 501 (1) ◽  
pp. 1426-1439
Author(s):  
Bernard Carr ◽  
Sebastien Clesse ◽  
Juan García-Bellido
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Selection Effect ◽  
Mass Function ◽  
Baryon Asymmetry ◽  
Primordial Black Holes ◽  
Cosmological Horizon ◽  
Chandrasekhar Limit ◽  
The Universe ◽  
Characteristic Mass

ABSTRACT If primordial black holes (PBHs) formed at the quark-hadron epoch, their mass must be close to the Chandrasekhar limit, this also being the characteristic mass of stars. If they provide the dark matter (DM), the collapse fraction must be of order the cosmological baryon-to-photon ratio ∼10−9, which suggests a scenario in which a baryon asymmetry is produced efficiently in the outgoing shock around each PBH and then propagates to the rest of the Universe. We suggest that the temperature increase in the shock provides the ingredients for hotspot electroweak baryogenesis. This also explains why baryons and DM have comparable densities, the precise ratio depending on the size of the PBH relative to the cosmological horizon at formation. The observed value of the collapse fraction and baryon asymmetry depends on the amplitude of the curvature fluctuations that generate the PBHs and may be explained by an anthropic selection effect associated with the existence of galaxies. We propose a scenario in which the quantum fluctuations of a light stochastic spectator field during inflation generate large curvature fluctuations in some regions, with the stochasticity of this field providing the basis for the required selection. Finally, we identify several observational predictions of our scenario that should be testable within the next few years. In particular, the PBH mass function could extend to sufficiently high masses to explain the black hole coalescences observed by LIGO/Virgo.

scholarly journals N-Body Results on Dark Matter

1987 ◽  
Vol 117 ◽  
pp. 263-278
Author(s):  
Simon D. M. White
Keyword(s):  
Dark Matter ◽  
Mass Distribution ◽  
Cold Dark Matter ◽  
Density Fluctuations ◽  
Major Difficulty ◽  
Mass Distributions ◽  
Galaxy Distribution ◽  
Galaxy Halos ◽  
Flat Rotation Curves ◽  
The Universe

The structure of the dominant “dark” component of the Universe may evolve primarily under the influence of gravity. A number of models for the evolution of the Universe make specific predictions for the statistical properties of density fluctuations at early times. N-body simulations can follow the nonlinear development of such fluctuations to the present day. A major difficulty arises because we cannot observe the present mass distribution directly. Recent N-body work has concentrated on models dominated by weakly interacting free elementary particles. Neutrino-dominated but otherwise conventional cosmologies pass rapidly from a smooth distribution to one dominated by lumps with masses greater than those of any known object. Cosmologies dominated by “cold dark matter” produce mass distributions which fit the observed galaxy distribution (i) if Ω = 0.1–0.2 and galaxies follow the mass distribution, or (ii) if Ω = 1, HO< 50 km/s/Mpc and galaxies form preferentially in high density regions. In the latter case, clumps form with flat rotation curves with about the amplitude and abundance expected for galaxy halos.

THE LHC AND THE UNIVERSE AT LARGE

2009 ◽  
Vol 24 (04) ◽  
pp. 657-669 ◽  
Author(s):  
PIERRE BINÉTRUY
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Dark Matter ◽  
Extra Dimensions ◽  
Beyond The Standard Model ◽  
Electroweak Phase Transition ◽  
Primordial Gravitational Waves ◽  
The Standard Model ◽  
Particle Astrophysics ◽  
The Universe

I discuss here some of the deeper connections between the physics studied at the LHC (electroweak phase transition, physics beyond the Standard Model, extra dimensions) and some of the most important issues in the field of particle astrophysics and cosmology (dark matter, primordial gravitational waves, black holes,…).

Primordial black holes and the observable features of the universe

2015 ◽  
Vol 24 (13) ◽  
pp. 1545005 ◽  
Author(s):  
K. M. Belotsky ◽  
A. A. Kirillov ◽  
S. G. Rubin
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Galactic Center ◽  
Mass Range ◽  
Primordial Black Holes ◽  
Simultaneous Solution ◽  
Supermassive Black Hole ◽  
Range Distribution ◽  
The Universe

Here, we briefly discuss the possibility to solve simultaneously with primordial black holes (PBHs) the problems of dark matter (DM), reionization of the universe, origin of positron line from Galactic center and supermassive black hole (BH) in it. Discussed scenario can naturally lead to a multiple-peak broad-mass-range distribution of PBHs in mass, which is necessary for simultaneous solution of the problems.

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 Primordial Black Holes as Dark Matter: Recent Developments

2020 ◽  
Vol 70 (1) ◽  
pp. 355-394 ◽  
Author(s):  
Bernard Carr ◽  
Florian Kühnel
Keyword(s):  
Elementary Particle ◽  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Cold Dark Matter ◽  
Galactic Nuclei ◽  
Matter Density ◽  
Primordial Black Holes ◽  
Poisson Effect ◽  
Recent Developments

Although the dark matter is usually assumed to be made up of some form of elementary particle, primordial black holes (PBHs) could also provide some of it. However, various constraints restrict the possible mass windows to 1016–1017 g, 1020–1024 g, and 10–103 M⊙. The last possibility is contentious but of special interest in view of the recent detection of black hole mergers by LIGO/Virgo. PBHs might have important consequences and resolve various cosmological conundra even if they account for only a small fraction of the dark matter density. In particular, those larger than 103 M⊙ could generate cosmological structures through the seed or Poisson effect, thereby alleviating some problems associated with the standard cold dark matter scenario, and sufficiently large PBHs might provide seeds for the supermassive black holes in galactic nuclei. More exotically, the Planck-mass relics of PBH evaporations or stupendously large black holes bigger than 1012 M⊙ could provide an interesting dark component.

scholarly journals PRIMORDIAL BLACK HOLES, HAWKING RADIATION AND THE EARLY UNIVERSE

2005 ◽  
Vol 20 (21) ◽  
pp. 1573-1576 ◽  
Author(s):  
PAUL H. FRAMPTON ◽  
THOMAS W. KEPHART
Keyword(s):  
Black Holes ◽  
Early Universe ◽  
Hawking Radiation ◽  
Cold Dark Matter ◽  
Primordial Black Holes ◽  
Gamma Emission ◽  
High Concentration ◽  
Age Of The Universe ◽  
Speculative Hypothesis ◽  
The Universe

The 511 keV gamma emission from the galactic core may originate from a high concentration (~ 1022) of primordial black holes (PBHs) in the core, each of whose Hawking radiation includes ~ 1021 positrons per second. The PBHs we consider are taken as near the lightest with longevity greater than the age of the universe (mass ~ 1012 kg ; Schwarzschild radius ~ 1 fm ). These PBHs contribute only a small fraction of cold dark matter, Ω PBH ~ 10-8. This speculative hypothesis, if confirmed implies the simultaneous discovery of Hawking radiation and an early universe phase transition.

scholarly journals A Brief Review on Primordial Black Holes as Dark Matter

2021 ◽  
Vol 8 ◽  
Author(s):  
Pablo Villanueva-Domingo ◽  
Olga Mena ◽  
Sergio Palomares-Ruiz
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Primordial Black Holes ◽  
Evolution Of The Universe ◽  
Matter Effects ◽  
The Universe ◽  
Hawking Evaporation

Primordial black holes (PBHs) represent a natural candidate for one of the components of the dark matter (DM) in the Universe. In this review, we shall discuss the basics of their formation, abundance and signatures. Some of their characteristic signals are examined, such as the emission of particles due to Hawking evaporation and the accretion of the surrounding matter, effects which could leave an impact in the evolution of the Universe and the formation of structures. The most relevant probes capable of constraining their masses and population are discussed.

scholarly journals On the origin and nature of dark matter

2018 ◽  
Vol 33 (32) ◽  
pp. 1830030 ◽  
Author(s):  
P. H. Frampton
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Second Law Of Thermodynamics ◽  
Light Curves ◽  
Primordial Black Holes ◽  
Intermediate Mass ◽  
Astrophysical Objects ◽  
Leading Particle ◽  
One Year ◽  
The Universe

It is discussed how the ideas of entropy and the second law of thermodynamics, conceived long ago during the nineteenth century, underly why cosmological dark matter exists and originated in the first three years of the universe in the form of primordial black holes, a very large number of which have many solar masses including up to the supermassive black holes at the centres of galaxies. Certain upper bounds on dark astrophysical objects with many solar masses based on analysis of the CMB spectrum and published in the literature are criticised. For completeness we discuss WIMPs and axions which are leading particle theory candidates for the constituents of dark matter. The PIMBHs (Primordial Intermediate Mass Black Holes) with many solar masses should be readily detectable in microlensing experiments which search the Magallenic Clouds and measure light curves with durations of from one year up to several years.

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