Quantum probing of singularities at event horizons of black holes

2021 ◽  
pp. 2150147
Author(s):  
V. P. Neznamov
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Mechanics ◽  
Event Horizon ◽  
Stationary States ◽  
Coordinate Transformations ◽  
Event Horizons ◽  
Schwarzschild Metric

It is proved that coordinate transformations of the Schwarzschild metric to new static and stationary metrics do not eliminate the mode of a particle “fall” to the event horizon of a black hole. This mode is unacceptable for the quantum mechanics of stationary states.

Entropy bound of horizons of some regular black holes

2020 ◽  
Vol 35 (10) ◽  
pp. 2050070
Author(s):  
Ujjal Debnath
Keyword(s):  
Black Holes ◽  
Heat Capacity ◽  
Black Hole ◽  
Specific Heat ◽  
Surface Area ◽  
Event Horizon ◽  
Specific Heat Capacity ◽  
Thermodynamic Quantities ◽  
Event Horizons ◽  
Regular Black Hole

We study the four-dimensional (i) modified Bardeen black hole, (ii) modified Hayward black hole, (iii) charged regular black hole and (iv) magnetically charged regular black hole. For modified Bardeen black hole and modified Hayward black hole, we found only one horizon (event horizon) and then we found some thermodynamic quantities like the entropy, surface area, irreducible mass, temperature, Komar energy and specific heat capacity on the event horizon. We here study the bounds of the above thermodynamic quantities for these black holes on the event horizon. Then, we examine the thermodynamics stability of the black holes with some conditions. Next, we studied the charged regular black hole and magnetically charged regular black hole and found two horizons (Cauchy and event horizons) of these black holes. Then, we found the entropy, surface area, irreducible mass, temperature, Komar energy and specific heat capacity on the Cauchy and event horizons. Then, we get some conditions for thermodynamic stability/instability of the black holes. We found the radius of the extremal horizon and Christodoulou–Ruffiini mass and then analyze the above thermodynamic quantities on the extremal horizon. We calculate the sum/subtraction, product, division and sum/subtraction of inverse of surface areas, entropies, irreducible masses, temperatures, Komar energies and specific heat capacities on both the horizons. From these, we found the bounds of the above quantities on the horizons.

scholarly journals A Note on the Observational Evidence for the Existence of Event Horizons in Astrophysical Black Hole Candidates

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Cosimo Bambi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Electromagnetic Radiation ◽  
Event Horizon ◽  
Observational Evidence ◽  
Short Paper ◽  
Event Horizons ◽  
Internal Region ◽  
The Universe ◽  
Black Hole Candidates

Black holes have the peculiar and intriguing property of having an event horizon, a one-way membrane causally separating their internal region from the rest of the Universe. Today, astrophysical observations provide some evidence for the existence of event horizons in astrophysical black hole candidates. In this short paper, I compare the constraint we can infer from the nonobservation of electromagnetic radiation from the putative surface of these objects with the bound coming from the ergoregion instability, pointing out the respective assumptions and limitations.

scholarly journals Physical Properties of Schwarzschild–deSitter Event Horizon Induced by Stochastic Quantum Gravity

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 511
Author(s):  
Claudio Cremaschini ◽  
Massimo Tessarotto
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Event Horizon ◽  
Field Equations ◽  
Central Mass ◽  
Event Horizons ◽  
Covariant Quantum ◽  
Gravitational Fields ◽  
New Type

A new type of quantum correction to the structure of classical black holes is investigated. This concerns the physics of event horizons induced by the occurrence of stochastic quantum gravitational fields. The theoretical framework is provided by the theory of manifestly covariant quantum gravity and the related prediction of an exclusively quantum-produced stochastic cosmological constant. The specific example case of the Schwarzschild–deSitter geometry is looked at, analyzing the consequent stochastic modifications of the Einstein field equations. It is proved that, in such a setting, the black hole event horizon no longer identifies a classical (i.e., deterministic) two-dimensional surface. On the contrary, it acquires a quantum stochastic character, giving rise to a frame-dependent transition region of radial width δr between internal and external subdomains. It is found that: (a) the radial size of the stochastic region depends parametrically on the central mass M of the black hole, scaling as δr∼M3; (b) for supermassive black holes δr is typically orders of magnitude larger than the Planck length lP. Instead, for typical stellar-mass black holes, δr may drop well below lP. The outcome provides new insight into the quantum properties of black holes, with implications for the physics of quantum tunneling phenomena expected to arise across stochastic event horizons.

scholarly journals Quantum Hair on Colliding Black Holes

Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 301
Author(s):  
Lawrence Crowell ◽  
Christian Corda
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Mechanics ◽  
Quantum Information ◽  
Excited States ◽  
Gravitational Radiation ◽  
Quantum Physics ◽  
Quantum Limit ◽  
Event Horizons ◽  
Quasi Normal Mode

Black hole (BH) collisions produce gravitational radiation which is generally thought, in a quantum limit, to be gravitons. The stretched horizon of a black hole contains quantum information, or a form of quantum hair, which is a coalescence of black holes participating in the generation of gravitons. This may be facilitated with a Bohr-like approach to black hole (BH) quantum physics with quasi-normal mode (QNM) approach to BH quantum mechanics. Quantum gravity and quantum hair on event horizons is excited to higher energy in BH coalescence. The near horizon condition for two BHs right before collision is a deformed A d S spacetime. These excited states of BH quantum hair then relax with the production of gravitons. This is then argued to define RT entropy given by quantum hair on the horizons. These qubits of information from a BH coalescence should then appear in gravitational wave (GW) data.

scholarly journals A spherically topological analysis of stationary black holes

2018 ◽  
Vol 1 ◽  
pp. 33-36
Author(s):  
Benjamin Puzantian
Keyword(s):  
Black Holes ◽  
Signal Processing ◽  
Black Hole ◽  
Angular Momentum ◽  
Fourier Analysis ◽  
Event Horizon ◽  
Topological Analysis ◽  
Stationary Black Hole ◽  
Einstein's Equations ◽  
Schwarzschild Metric

A black hole with zero angular momentum is said to be stationary and under certain conditions such a black hole can represented as a sphere. This review examines Hawking’s topology theorem, the Schwarzschild metric, novel solutions to Einstein’s equations, resonances of hyperbolic orbits around the event horizon for spherical, stationary black holes, and analyzes their importance. It is suggested, that in the spherical stationary black hole case, the Fourier analysis can be used to find the resonances due to Geometric scattering of hyperbolic orbits and thus the outgoing energy fields from the event horizon can be found more precisely; allowing for the adequate signal processing analysis to be found for such a field.

The case for artificial black holes

2008 ◽  
Vol 366 (1877) ◽  
pp. 2851-2857 ◽  
Author(s):  
Ulf Leonhardt ◽  
Thomas G Philbin
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Quantum Mechanics ◽  
Event Horizon ◽  
Quantum Vacuum ◽  
Quantum Radiation

The event horizon is predicted to generate particles from the quantum vacuum, an effect that bridges three areas of physics—general relativity, quantum mechanics and thermodynamics. The quantum radiation of real black holes is too feeble to be detectable, but black-hole analogues may probe several aspects of quantum black holes. In this paper, we explain in simple terms some of the motivations behind the study of artificial black holes.

scholarly journals Mechanism for nonlocal information flow from black holes

2020 ◽  
Vol 35 (06) ◽  
pp. 2050031
Author(s):  
Adithya Kandhadai ◽  
Antony Valentini
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Mechanics ◽  
Event Horizon ◽  
Information Flow ◽  
Entangled State ◽  
Born Rule ◽  
Pilot Wave ◽  
De Broglie Bohm

We show that quantum nonequilibrium (or deviations from the Born rule) can propagate nonlocally across space. Such phenomena are allowed in the de Broglie–Bohm pilot-wave formulation of quantum mechanics. We show that an entangled state can act as a channel whereby quantum nonequilibrium can be transferred nonlocally from one region to another without any classical interaction. This suggests a novel mechanism whereby information can escape from behind the classical event horizon of an evaporating black hole.

Black Hole Exotica

2014 ◽  
Author(s):  
Charles D. Bailyn
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Mechanics ◽  
Event Horizon ◽  
Hawking Radiation ◽  
The Universe

This chapter explores some of the predicted effects of black holes on people's lives and the possibility that they might someday be explored in fact as well as in fiction. These predicted effects include the Hawking radiation, wormholes, and multiverses. The Hawking radiation—in which the interaction between quantum mechanics and relativity has been explored with some success—is a process through which black holes are expected to emit energy and ultimately evaporate. Meanwhile, one of the most enticing possible effects associated with black holes is that they might form wormholes through which widely separated parts of the Universe can be closely connected. Lastly, one final suggestion that might be contemplated is that a separate universe might exist inside the event horizon of a black hole. This is one version of the multiverse concept, in which a variety of universes with a variety of characteristics exist.

Supermassive Black Holes

2019 ◽  
pp. 151-158
Author(s):  
Nicholas Mee
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Event Horizon ◽  
Supermassive Black Holes ◽  
Radio Telescopes ◽  
Event Horizons ◽  
Supermassive Black Hole

The Event Horizon Telescope (EHT) is aiming to image the event horizon of the supermassive black hole at the centre of our galaxy. Andrea Ghez has mapped out the orbits of stars around this supermassive black hole and deduced it has a mass of four million Suns. An even bigger supermassive black hole of six billion solar masses lies at the centre of the M87 Galaxy. Shep Doeleman has marshalled several of the world’s radio telescopes to form the EHT with the aim of imaging the event horizons of these black holes.

scholarly journals Comments on information erasure in black hole

2014 ◽  
Vol 29 (38) ◽  
pp. 1450199
Author(s):  
Mishkat Al Alvi ◽  
Md. Abdul Matin ◽  
Moinul Hossain Rahat ◽  
Avik Roy ◽  
Mahbub Majumdar
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Mechanics ◽  
Mutual Information ◽  
Event Horizon ◽  
Physical Interpretation ◽  
Black Hole Horizon ◽  
Landauer’S Principle ◽  
Physical Laws ◽  
Information Erasure

We analyze the Kim, Lee and Lee model of information erasure by black holes and find contradictions with standard physical laws. We demonstrate that the erasure model leads to arbitrarily fast information erasure; the proposed physical interpretation of information freezing at the event horizon as observed by an asymptotic observer is problematic; and information erasure, whatever the process may be, near the black hole horizon leads to contradictions with quantum mechanics if Landauer's principle is assumed. The later part of the work demonstrates the significance of the "erasure entropy". We show that the erasure entropy is the mutual information between two subsystems.

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