scholarly journals PRE INFLATION MATTER ERA AND CMB ANOMALY

2012 ◽  
Vol 12 ◽  
pp. 390-399
Author(s):  
FABIO SCARDIGLI ◽  
CHRISTINE GRUBER ◽  
PISIN CHEN
Keyword(s):  
Black Holes ◽  
Power Spectrum ◽  
Observational Data ◽  
Early Universe ◽  
The Universe

We consider the production of primordial micro black holes (MBH) remnants in the early universe. These objects induce the universe to be in a matter-dominated era before the onset of inflation. Effects of such an epoch on the CMB power spectrum are discussed and computed both analytically and numerically. By comparison with the latest observational data from the WMAP collaboration, we find that our model appears to explain the quadrupole anomaly of the CMB power spectrum.

scholarly journals Discovery of the first heavily obscured QSO candidate at z > 6 in a close galaxy pair

2019 ◽  
Vol 628 ◽  
pp. L6 ◽  
Author(s):  
F. Vito ◽  
W. N. Brandt ◽  
F. E. Bauer ◽  
R. Gilli ◽  
B. Luo ◽  
...  
Keyword(s):  
Black Holes ◽  
Early Universe ◽  
Column Density ◽  
Early Growth ◽  
Point Of View ◽  
X Ray ◽  
Confidence Levels ◽  
The Universe ◽  
Companion Galaxy

While theoretical arguments predict that most of the early growth of supermassive black holes (SMBHs) happened during heavily obscured phases of accretion, current methods used for selecting z >  6 quasars (QSOs) are strongly biased against obscured QSOs, thus considerably limiting our understanding of accreting SMBHs during the first gigayear of the Universe from an observational point of view. We report the Chandra discovery of the first heavily obscured QSO candidate in the early universe, hosted by a close (≈5 kpc) galaxy pair at z = 6.515. One of the members is an optically classified type-1 QSO, PSO167–13. The companion galaxy was first detected as a [C II] emitter by Atacama large millimeter array (ALMA). An X-ray source is significantly (P = 0.9996) detected by Chandra in the 2–5 keV band, with < 1.14 net counts in the 0.5–2 keV band, although the current positional uncertainty does not allow a conclusive association with either PSO167–13 or its companion galaxy. From X-ray photometry and hardness-ratio arguments, we estimated an obscuring column density of NH >  2 × 1024 cm−2 and NH >  6 × 1023 cm−2 at 68% and 90% confidence levels, respectively. Thus, regardless of which of the two galaxies is associated with the X-ray emission, this source is the first heavily obscured QSO candidate at z >  6.

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 Massive primordial black holes in contemporary and young universe (old predictions and new data)

2018 ◽  
Vol 33 (31) ◽  
pp. 1844029 ◽  
Author(s):  
A. D. Dolgov
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Observational Data ◽  
High Population ◽  
Primordial Black Holes ◽  
Astronomical Data ◽  
The Universe

A brief review of the recent astronomical data, indicating that the universe is abundantly populated by heavy black holes (BH), is presented. Conventional astrophysics and cosmology cannot explain such a high population of BHs. A mechanism of the paper of 1963 is described, which at least qualitatively explained the observational data. In particular, the prediction that massive primordial BHs can be cosmological dark matter “particles” is discussed.

scholarly journals Black hole production of monopoles in the early universe

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Saurav Das ◽  
Anson Hook
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Temperature Profile ◽  
Early Universe ◽  
Hot Plasma ◽  
The Universe

Abstract In the early universe, evaporating black holes heat up the surrounding plasma and create a temperature profile around the black hole that can be more important than the black hole itself. As an example, we demonstrate how the hot plasma surrounding evaporating black holes can efficiently produce monopoles via the Kibble-Zurek mechanism. In the case where black holes reheat the universe, reheat temperatures above ∼ 500 GeV can already lead to monopoles overclosing the universe.

Inflation, dark matter, and dark energy

2019 ◽  
pp. 423-464
Author(s):  
Malcolm S. Longair ◽  
Chris Smeenk
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Power Spectrum ◽  
Early Universe ◽  
Particle Physics ◽  
Large Scale ◽  
Initial State ◽  
Large Scale Structures ◽  
Initial Power ◽  
The Universe

The success of the ΛCDM model has raised a number of challenging problems for the origin of structure in the universe and the initial state from which it evolved. The origins of these basic cosmological problems are described. The dark matter must be non-baryonic, but its nature has not been established. Likewise, the nature of the dark energy is not understood. The inflationary model for the very early universe has had some undoubted successes in accounting for the initial power-spectrum of fluctuations from which large-scale structures formed but there is no physical realization of the inflaton field. Defects formed during phase transitions in the early universe cannot account for the initial power spectrum of fluctuations, but may have some part to play in structure formation. The origin of the baryon-antibaryon asymmetry in the early universe is not understood in terms of theories of particle physics.

scholarly journals The Formation and Feeding of Massive Black Holes in the Early Universe

2002 ◽  
Vol 184 ◽  
pp. 343-349
Author(s):  
Wolfgang J. Duschl ◽  
Peter A. Strittmatter
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Observational Data ◽  
Early Universe ◽  
Time Scale ◽  
Short Time Scale ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
Open Question ◽  
Short Time

AbstractIt is still an open question whether the super-massive black holes thought to be present in quasars are of primordial nature, or whether there is a viable way of forming them in the very short time scale (less than a billion years) permitted by the observational data. In this contribution, we present a way in which a galaxy-galaxy merger can provide not only the “fuel” for quasar activity, but can also build a super-massive black hole, i.e., “the engine”, in the first place.

scholarly journals Signatures of primordial black hole dark matter

2014 ◽  
Vol 29 (37) ◽  
pp. 1440005 ◽  
Author(s):  
K. M. Belotsky ◽  
A. E. Dmitriev ◽  
E. A. Esipova ◽  
V. A. Gani ◽  
A. V. Grobov ◽  
...  
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Symmetry Breaking ◽  
Early Universe ◽  
High Energy Physics ◽  
Gamma Ray ◽  
High Energy ◽  
Primordial Black Hole ◽  
Dominant Form ◽  
The Universe

The nonbaryonic dark matter of the Universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro-world and mechanisms of its symmetry breaking. In the early Universe heavy metastable particles can dominate, leaving primordial black holes (PBHs) after their decay, as well as the structure of particle symmetry breaking gives rise to cosmological phase transitions, from which massive black holes (BHs) and/or their clusters can originate. PBHs can be formed in such transitions within a narrow interval of masses about 1017 g and, avoiding severe observational constraints on PBHs, can be a candidate for the dominant form of dark matter. PBHs in this range of mass can give solution of the problem of reionization in the Universe at the redshift z~5–10. Clusters of massive PBHs can serve as a nonlinear seeds for galaxy formation, while PBHs evaporating in such clusters can provide an interesting interpretation for the observations of point-like gamma-ray sources. Analysis of possible PBH signatures represents a universal probe for super-high energy physics in the early Universe in studies of indirect effects of the dark matter.

scholarly journals Black Holes in the Early Universe

1974 ◽  
Vol 64 ◽  
pp. 184-184
Author(s):  
Bernard J. Carr ◽  
Stephen W. Hawking
Keyword(s):  
Black Holes ◽  
Early Universe ◽  
Gravitational Collapse ◽  
Radiation Pressure ◽  
Initial Conditions ◽  
Particle Horizon ◽  
The Universe

The existence of galaxies indicates that the early universe must have been inhomogeneous and might have been highly chaotic. This could have lead to regions of the size of the particle horizon undergoing gravitational collapse to produce black holes with initial masses from 10-5 g upwards. Radiation pressure in the early Universe would cause these black holes to grow by accretion. However, despite previous expectations, this accretion would not be very much unless the initial conditions of the Universe were arranged in a special and a causal manner. Observations indicate that, at the most, only a small fraction of the matter in the early Universe can have undergone gravitational collapse.

Black holes in the Universe

2001 ◽  
Vol 171 (3) ◽  
pp. 307 ◽  
Author(s):  
Igor D. Novikov ◽  
Valerii P. Frolov
Keyword(s):  
Black Holes ◽  
The Universe

Beyond the Schwarzschild Metric

2018 ◽  
Author(s):  
David M. Wittman
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Gravitational Waves ◽  
Test Particle ◽  
Direct Detection ◽  
Relativistic Effects ◽  
Big Bang ◽  
Clusters Of Galaxies ◽  
General Relativistic ◽  
The Universe

General relativity explains much more than the spacetime around static spherical masses.We briefly assess general relativity in the larger context of physical theories, then explore various general relativistic effects that have no Newtonian analog. First, source massmotion gives rise to gravitomagnetic effects on test particles.These effects also depend on the velocity of the test particle, which has substantial implications for orbits around black holes to be further explored in Chapter 20. Second, any changes in the sourcemass ripple outward as gravitational waves, and we tell the century‐long story from the prediction of gravitational waves to their first direct detection in 2015. Third, the deflection of light by galaxies and clusters of galaxies allows us to map the amount and distribution of mass in the universe in astonishing detail. Finally, general relativity enables modeling the universe as a whole, and we explore the resulting Big Bang cosmology.

Sign in / Sign up

Export Citation Format

Share Document