scholarly journals Accretion disk around a Schwarzschild black hole in asymptotic safety

2021 ◽  
Vol 81 (9) ◽  
Author(s):  
Fabián H. Zuluaga ◽  
Luis A. Sánchez
Keyword(s):  
Black Hole ◽  
Thermal Properties ◽  
Quantum Gravity ◽  
Schwarzschild Black Hole ◽  
Spacetime Geometry ◽  
Black Hole Candidate ◽  
Stable Circular Orbit ◽  
Gravity Effects ◽  
Relativistic Regime ◽  
Higher Derivatives

AbstractWe study quantum gravity effects on radiation properties of thin accretion disks around a renormalization group improved (RGI-) Schwarzschild black hole. In the infrared (IR) limit of the asymptotically safe theory with higher derivatives, the running Newton coupling G(r) depends on a free parameter which encodes the quantum effects on the spacetime geometry. By varying this parameter, modifications to thermal properties of the disk as the time averaged energy flux, the disk temperature, the differential luminosity, and the conversion efficiency of accreting mass into radiation, are obtained. In addition to a shifting of the radius of the innermost stable circular orbit (ISCO) toward small values, we find an increase of the maximum values of these thermal properties and a greater efficiency than in the classical relativistic regime. We discuss astrophysical applications of these results by using observational data of the stellar-mass black hole candidate LMC X-3. Our findings could, in principle, be used to identify quantum gravity effects through astrophysical observations.

scholarly journals A PROPOSAL TO RESOLVE THE BLACK HOLE INFORMATION PARADOX

2002 ◽  
Vol 11 (10) ◽  
pp. 1537-1540 ◽  
Author(s):  
SAMIR D. MATHUR
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Quantum Gravity ◽  
Bound State ◽  
Nonlocal Effects ◽  
Information Paradox ◽  
Microscopic Scale ◽  
Gravity Effects ◽  
Black Hole Information

The entropy and information puzzles arising from black holes cannot be resolved if quantum gravity effects remain confined to a microscopic scale. We use concrete computations in nonperturbative string theory to argue for three kinds of nonlocal effects that operate over macroscopic distances. These effects arise when we make a bound state of a large number of branes, and occur at the correct scale to resolve the paradoxes associated with black holes.

Quantum gravity effects on scalar particle tunneling from rotating BTZ black hole

2018 ◽  
Vol 33 (12) ◽  
pp. 1850070 ◽  
Author(s):  
I. Ablu Meitei ◽  
T. Ibungochouba Singh ◽  
S. Gayatri Devi ◽  
N. Premeshwari Devi ◽  
K. Yugindro Singh
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Generalized Uncertainty Principle ◽  
Scalar Particle ◽  
Mass Energy ◽  
Btz Black Hole ◽  
Logarithmic Term ◽  
Scalar Particles ◽  
Gravity Effects ◽  
Correction Terms

Tunneling of scalar particles across the event horizon of rotating BTZ black hole is investigated using the Generalized Uncertainty Principle to study the corrected Hawking temperature and entropy in the presence of quantum gravity effects. We have determined explicitly the various correction terms in the entropy of rotating BTZ black hole including the logarithmic term of the Bekenstein–Hawking entropy [Formula: see text], the inverse term of [Formula: see text] and terms with inverse powers of [Formula: see text], in terms of properties of the black hole and the emitted particles — mass, energy and angular momentum. In the presence of quantum gravity effects, for the emission of scalar particles, the Hawking radiation and thermodynamics of rotating BTZ black hole are observed to be related to the metric element, hence to the curvature of space–time.

Effect of post-Newtonian-like self-energy, quantum gravity and exchange correlations on Schwarzschild black hole: Application of uncertainty principle

2020 ◽  
Vol 35 (11) ◽  
pp. 2050081
Author(s):  
Baljeet Kaur Lotte ◽  
Subodha Mishra
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Correlation Energy ◽  
Particle System ◽  
Gravitational Interaction ◽  
Schwarzschild Black Hole ◽  
Loop Contribution ◽  
Exchange Correlation ◽  
Self Energy ◽  
Energy Quantum

The expressions for the corrected radius and the Hawking temperature of a Schwarzschild black hole are derived by calculating the total energy of a self-gravitating system of N fermions when the corrections to gravitational interaction due to post-Newtonian-like self-energy due to two graviton exchange- and one-loop contribution of quantum gravity effect are included. Since the particles are fermions, the exchange-correlation energy is also included consistently. It is found that though the three corrections are small, the correction due to the exchange-correlation is much more than the other two. The configuration of the many-particle system that we study is possible since it has no Buchdahl limit in the post-Newtonian approximation.

scholarly journals Quantum gravity effects on Hořava–Lifshitz black hole

2018 ◽  
Vol 928 ◽  
pp. 415-434 ◽  
Author(s):  
B. Pourhassan ◽  
S. Upadhyay ◽  
H. Saadat ◽  
H. Farahani
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Gravity Effects ◽  
Lifshitz Black Hole

scholarly journals Quantum gravity effects around Sagittarius A*

2016 ◽  
Vol 25 (12) ◽  
pp. 1644021 ◽  
Author(s):  
Hal M. Haggard ◽  
Carlo Rovelli
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Event Horizon ◽  
Sagittarius A ◽  
Vlbi Observations ◽  
Gravity Effects ◽  
Sgr A ◽  
Schwarzschild Radius ◽  
Number Of Authors

Recent VLBI observations have resolved Sagittarius A* at horizon scales. The event horizon telescope is expected to provide increasingly good images of the region around the Schwarzschild radius [Formula: see text] of Sgr A* soon. A number of authors have recently pointed out the possibility that nonperturbative quantum gravitational phenomena could affect the space surrounding a black hole. Here, we point out that the existence of a region around [Formula: see text], where these effects should be maximal.

Quantum Gravity Effects on the Tunneling Radiation of the Einstein-Maxwell-Dilaton-Axion Black Hole

2016 ◽  
Vol 55 (7) ◽  
pp. 3173-3180 ◽  
Author(s):  
Tianhu Cheng ◽  
Ruyi Ren ◽  
Deyou Chen ◽  
Zixiang Liu ◽  
Guopin Li
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Tunneling Radiation ◽  
Gravity Effects

scholarly journals Geodesic motion near self-gravitating scalar field configurations

2019 ◽  
Vol 27 (3) ◽  
pp. 231-241
Author(s):  
Ivan M. Potashov ◽  
Julia V. Tchemarina ◽  
Alexander N. Tsirulev
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Circular Orbit ◽  
Naked Singularity ◽  
Schwarzschild Black Hole ◽  
Null Geodesics ◽  
Naked Singularities ◽  
Test Particles ◽  
Stable Circular Orbit ◽  
Innermost Stable Circular Orbit

We study the geodesics motion of neutral test particles in the static spherically symmetric spacetimes of black holes and naked singularities supported by a selfgravitating real scalar field. The scalar field is supposed to model dark matter surrounding some strongly gravitating object such as the centre of our Galaxy. The behaviour of timelike and null geodesics very close to the centre of such a configuration crucially depends on the type of spacetime. It turns out that a scalar field black hole, analogously to a Schwarzschild black hole, has the innermost stable circular orbit and the (unstable) photon sphere, but their radii are always less than the corresponding ones for the Schwarzschild black hole of the same mass; moreover, these radii can be arbitrarily small. In contrast, a scalar field naked singularity has neither the innermost stable circular orbit nor the photon sphere. Instead, such a configuration has a spherical shell of test particles surrounding its origin and remaining in quasistatic equilibrium all the time. We also show that the characteristic properties of null geodesics near the centres of a scalar field naked singularity and a scalar field black hole of the same mass are qualitatively different.

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