scholarly journals Quantum leaps of black holes: Magnifying glasses of quantum gravity

2016 ◽  
Vol 25 (12) ◽  
pp. 1644024 ◽  
Author(s):  
Sumanta Chakraborty ◽  
Kinjalk Lochan
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
The Third

We show using simple arguments, that the conceptual triad of a classical black hole, semi-classical Hawking emission and geometry quantization is inherently, mutually incompatible. Presence of any two explicitly violates the third. We argue that geometry quantization, if realized in nature, magnifies the quantum gravity features hugely to catapult them into the realm of observational possibilities. We also explore a quantum route towards extremality of the black holes.

scholarly journals Massive Gravitational Waves from Black Hole Inspirals in Quantum Gravity

2018 ◽  
Vol 191 ◽  
pp. 07003
Author(s):  
Xavier Calmet ◽  
Boris Latosh
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Gravitational Waves ◽  
Emission Rate ◽  
New States ◽  
Model Independent ◽  
Classical Fields ◽  
Using Data

We show that alongside the already observed gravitational waves, quantum gravity predicts the existence of two additional massive classical fields and thus two new massive waves. We set a limit on their masses using data from Eöt-Wash-like experiments. We point out that the existence of these new states is a model independent prediction of quantum gravity. We explain how these new classical fields could impact astrophysical processes and in particular the binary inspirals of black holes. We calculate the emission rate of these new states in binary inspirals astrophysical processes.

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.

scholarly journals What prevents gravitational collapse in string theory?

2016 ◽  
Vol 25 (12) ◽  
pp. 1644018 ◽  
Author(s):  
Samir D. Mathur
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Quantum Gravity ◽  
State Space ◽  
Dimensional Reduction ◽  
Extra Dimension ◽  
Mass Formula ◽  
Compact Dimension ◽  
Classical Gravity

It is conventionally believed that if a ball of matter of mass [Formula: see text] has a radius close to [Formula: see text][Formula: see text]GM then it must collapse to a black hole. But string theory microstates (fuzzballs) have no horizon or singularity, and they do not collapse. We consider two simple examples from classical gravity to illustrate how this violation of our intuition happens. In each case, the ‘matter’ arises from an extra compact dimension, but the topology of this extra dimension is not trivial. The pressure and density of this matter diverge at various points, but this is only an artifact of dimensional reduction; thus, we bypass results like Buchadahl’s theorem. Such microstates give the entropy of black holes, so these topologically nontrivial constructions dominate the state space of quantum gravity.

scholarly journals Evaporation of black hole under the effect of quantum gravity

2021 ◽  
Author(s):  
Riasat Ali ◽  
Rimsha Babar ◽  
Muhammad Asgher ◽  
Syed Asif Ali Shah
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Generalized Uncertainty Principle ◽  
Hawking Temperature ◽  
Charged Black Hole ◽  
Global Monopole ◽  
De Sitter ◽  
Quantum Radiation ◽  
Charged Boson

This paper provides an extension for Hawking temperature of Reissner–Nordström-de Sitter (RN-DS) black hole (BH) with global monopole as well as [Formula: see text]D charged black hole. We consider the black holes metric and investigate the effects of quantum gravity ([Formula: see text]) on Hawking radiation. We investigate the charged boson particles tunneling through the horizon of black holes by using the Hamilton–Jacobi ansatz phenomenon. In our investigation, we study the quantum radiation to analyze the Lagrangian wave equation with generalized uncertainty principle and calculate the modified Hawking temperatures for black holes. Furthermore, we analyze the charge and correction parameter effects on the modified Hawking temperature and examine the stable and unstable condition of RN-DS BH with global monopole as well as [Formula: see text]D charged black hole.

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.

The Direct Detection of Gravitational Waves

2018 ◽  
pp. 106-109
Author(s):  
Alvaro De Rújula
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Gravitational Waves ◽  
Direct Detection ◽  
Space Time ◽  
New Era ◽  
The Third ◽  
Perfect Storm

Gravitational waves emitted by black hole mergers. The first LIGO event: GW150917, the coalescence of two black holes of twenty nine and thirty six solar masses into one of “only” sixty two. The remaining three solar masses were emitted as energy in gravitational waves, a gigantic and perfect storm in the fabric of space-time. This is the dawn of a new era: The opening of the third “window” through which to look at the sky. Yet another triumph of general relativity. How much progress astrophysics has made since my time as a student.

The remnants in Reissner–Nordström–de Sitter quintessence black hole

2014 ◽  
Vol 29 (26) ◽  
pp. 1450123 ◽  
Author(s):  
Zhongwen Feng ◽  
Li Zhang ◽  
Xiaotao Zu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Quantum Number ◽  
Information Loss ◽  
De Sitter ◽  
Information Loss Paradox

According to the effects of quantum gravity, we investigated the fermion tunneling from the Reissner–Nordström–de Sitter quintessence (RN–dSQ) black hole. The corrected temperature is not only determined by the mass and charge of the black hole, but also depended on the quantum number of the emitted fermion and β, which is a small value representing the effects of quantum gravity. The effects of quantum gravity slowed down the increase of the temperature and led to the remnants of the black hole. We think it is a method to avoid the information loss paradox of black holes.

scholarly journals NONCOMMUTATIVE BLACK HOLES, THE FINAL APPEAL TO QUANTUM GRAVITY: A REVIEW

2009 ◽  
Vol 24 (07) ◽  
pp. 1229-1308 ◽  
Author(s):  
PIERO NICOLINI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Effective Theory ◽  
Final State ◽  
Curved Space ◽  
Higher Dimensional ◽  
Energy Hadron ◽  
Black Hole Remnant ◽  
First Time

We present the state of the art regarding the relation between the physics of Quantum Black Holes and Noncommutative Geometry. We start with a review of models proposed in the literature for describing deformations of General Relativity in the presence of noncommutativity, seen as an effective theory of Quantum Gravity. We study the resulting metrics, proposed to replace or at least to improve the conventional black hole solutions of Einstein's equation. In particular, we analyze noncommutative-inspired solutions obtained in terms of quasiclassical noncommutative coordinates: indeed because of their surprising new features, these solutions enable us to circumvent long standing problems with Quantum Field Theory in Curved Space and to cure the singular behavior of gravity at the centers of black holes. As a consequence, for the first time, we get a complete description of what we may call the black hole SCRAM, the shut down of the emission of thermal radiation from the black hole: in place of the conventional scenario of runaway evaporation in the Planck phase, we find a zero temperature final state, a stable black hole remnant, whose size and mass are determined uniquely in terms of the noncommutative parameter θ. This result turns out to be of vital importance for the physics of the forthcoming experiments at the LHC, where mini black hole production is foreseen in extreme energy hadron collisions. Because of this, we devote the final part of this review to higher-dimensional solutions and their phenomenological implications for TeV Gravity.

scholarly journals Overspinning Kerr-MOG black holes by test fields and the third law of black hole dynamics

2020 ◽  
Vol 80 (1) ◽  
Author(s):  
Koray Düztaş
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Velocity ◽  
Weak Form ◽  
Scalar Fields ◽  
Cosmic Censorship ◽  
Test Field ◽  
Naked Singularities ◽  
The Third ◽  
Third Law

AbstractWe evaluate the validity of the weak form of the cosmic censorship conjecture and the third law of black hole dynamics for Kerr-MOG black holes interacting with test scalar fields. Ignoring backreaction effects, we first show that both extremal and nearly extremal Kerr-MOG black holes can be overspun into naked singularities by test fields with a frequency slightly above the superradiance limit. In addition, nearly extremal Kerr-MOG black holes can be continuously driven to extremality by test fields. Next, we employ backreaction effects based on the argument that the angular velocity of the event horizon increases before the absorption of the test field. Incorporating the backreaction effects, we derive that the weak form of the cosmic censorship and the third law are both valid for Kerr-MOG black holes with a modification parameter $$\alpha \lesssim 0.03$$α≲0.03, which includes the Kerr case with $$\alpha =0$$α=0.

scholarly journals BLACK HOLES AND THE THIRD LAW OF THERMODYNAMICS

2004 ◽  
Vol 13 (04) ◽  
pp. 739-770 ◽  
Author(s):  
F. BELGIORNO ◽  
M. MARTELLINI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Second Law Of Thermodynamics ◽  
Temperature Limit ◽  
Black Hole Thermodynamics ◽  
Zero Temperature ◽  
The Third ◽  
Third Law Of Thermodynamics ◽  
Third Law ◽  
Extremal Black Holes

We discuss in the framework of black hole thermodynamics some aspects relative to the third law in the case of black holes of the Kerr–Newman family. In the light of the standard proof of the equivalence between the unattainability of the zero temperature and the entropic version of the third law it is remarked that the unattainability has a special character in black hole thermodynamics. Also the zero temperature limit which obtained in the case of very massive black holes is discussed and it is shown that a violation of the entropic version in the charged case occurs. The violation of the Bekenstein–Hawking law in favour of zero entropy SE=0 in the case of extremal black holes is suggested as a natural solution for a possible violation of the second law of thermodynamics. Thermostatic arguments in support of the unattainability are explored, and SE=0 for extremal black holes is shown to be again a viable solution. The third law of black hole dynamics by W. Israel is then interpreted as a further strong corroboration to the picture of a discontinuity between extremal states and non-extremal ones.

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