scholarly journals Embedding into flat spacetime and black hole thermodynamics

2019 ◽  
Vol 35 (05) ◽  
pp. 2050013 ◽  
Author(s):  
T. R. Govindarajan ◽  
Sumanta Chakraborty
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Thermodynamic Description ◽  
Scaling Law ◽  
Black Hole Entropy ◽  
Flat Spacetime ◽  
Higher Dimensional ◽  
Black Hole Spacetime ◽  
Symmetric Black Hole ◽  
Black Hole Temperature

It is known that static and spherically symmetric black hole solutions of general relativity in different spacetimes can be embedded into higher-dimensional flat spacetime. Given this result, we have explored the thermodynamic nature of black holes á la its embedding into flat spacetime. In particular, we have explicitly demonstrated that black hole temperature can indeed be determined starting from the embedding and hence mapping of the static observers in black hole spacetime to Rindler observers in flat spacetime. Furthermore, by considering the dynamics of a scalar field in the flat spacetime, it is indeed possible to arrive at the area scaling law for black hole entropy. Thus, by using the flat spacetime field theory, one can indeed provide a thermodynamic description of black holes. Implications are also discussed.

scholarly journals From microscopic black hole entropy toward Hawking radiationc

2020 ◽  
Vol 29 (14) ◽  
pp. 2043031
Author(s):  
Jun Nian ◽  
Leopoldo A. Pando Zayas
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Entropy ◽  
Extremal Black Hole ◽  
Novel Approach ◽  
Ads Black Holes ◽  
Higher Dimensional ◽  
Dimensional Boundary ◽  
Horizon Limit ◽  
Extremal Black Holes

The AdS/CFT correspondence has recently provided a novel approach for counting the microstates of black holes impressively matching the macroscopic Bekenstein–Hawking entropy formula of rotating electrically charged asymptotically AdS black holes in four to seven dimensions. This approach is designed for supersymmetric extremal black holes, but can also be extended to nonsupersymmetric, near-extremal black holes. Besides the dual higher-dimensional boundary CFT, an effective 2D CFT emerges in a certain near-horizon limit accounting for both the extremal and the near-extremal black hole entropies. This effective 2D description is universal across dimensions and comes naturally equipped with an approach to quantitatively tackle aspects of Hawking radiation.

Wormholes, Time Travel, and Other Exotic Theories

2020 ◽  
pp. 72-87
Author(s):  
John W. Moffat
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Waves ◽  
Black Hole Entropy ◽  
Negative Energy ◽  
Superstring Theory ◽  
Quantum Radiation ◽  
Higher Dimensional ◽  
Mathematical Equations ◽  
The Universe

In 1935, Einstein and Rosen described what is now called the Einstein-Rosen bridge. Wheeler called this a wormhole, which could connect two distant parts of the universe. Thorne and Morris showed the wormhole cannot be traversable unless exotic matter with negative energy props it up. Using the Penrose mechanism of superradiance, one can produce rotational energy from a black hole, which could be used to detect dark matter particles. Higher dimensional objects such as branes in superstring theory have been considered as sources of gravitational waves. Black holes have even been proposed to be giant atoms, related to Hawking radiation and black hole entropy. Bekenstein and Mukhanov postulated that black holes radiated quantum radiation. Many such speculative ideas have been put forth that could potentially be verified by detecting gravitational waves. Yet, many physicists work with mathematical equations, unconcerned with whether their ideas can be verified or falsified by experiments.

scholarly journals THERMODYNAMICS OF NONSPHERICAL BLACK HOLES FROM LIOUVILLE THEORY

2012 ◽  
Vol 27 (20) ◽  
pp. 1250111 ◽  
Author(s):  
FANG-FANG YUAN ◽  
YONG-CHANG HUANG
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Central Charge ◽  
Black Hole Entropy ◽  
Liouville Theory ◽  
Two Dimensional ◽  
Hamiltonian Approach ◽  
Black Rings ◽  
Dimensional Black Hole ◽  
Black Hole Temperature

A Liouville formalism was proposed many years ago to account for the black hole entropy. It was recently updated to connect thermodynamics of general black holes, in particular the Hawking temperature, to two-dimensional Liouville theory. This relies on the dimensional reduction to two-dimensional black hole metric. The relevant dilaton gravity model can be rewritten as a Liouville-like theory. We refine the method and give general formulas for the corresponding scalar and energy–momentum tensors in Liouville theory. This enables us to read off the black hole temperature using a relation which was found about three decades ago. Then the range of application is extended to include nonspherical black holes such as neutral and charged black rings, topological black hole and the case coupled to a scalar field. As for the entropy, following previous authors, we invoke the Lagrangian approach to central charge by Cadoni and then use the Cardy formula. The general relevant parameters are also given. This approach is more advantageous than the usual Hamiltonian approach which was used by the old Liouville formalism for black hole entropy.

scholarly journals Quasi-normal modes of near-extremal black holes in generalized spherically symmetric spacetime and strong cosmic censorship conjecture

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Piyabut Burikham ◽  
Supakchai Ponglertsakul ◽  
Taum Wuthicharn
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Normal Modes ◽  
Cosmic Censorship ◽  
Analytic Formula ◽  
Spherically Symmetric ◽  
Black Hole Background ◽  
Strong Cosmic Censorship ◽  
Black Hole Spacetime ◽  
Symmetric Black Hole

AbstractA number of near-extremal conditions are utilized to simplify the equation of motion of the neutral scalar perturbations in generalized spherically symmetric black hole background into a differential equation with the Pöschl–Teller potential. An analytic formula for quasinormal frequencies is obtained. The analytic formula is then used to investigate strong cosmic censorship conjectures (SCC) of the generalized black hole spacetime for the smooth initial data. The Christodoulou version of the SCC is found to be violated for certain regions of the black hole parameter space including the black holes in general relativity while the $$C^{1}$$ C 1 version of the SCC is always valid.

scholarly journals Microscopic entropy of AdS3 black holes revisited

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Finn Larsen ◽  
Siyul Lee
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Entropy ◽  
Canonical Partition Function ◽  
Microscopic Description ◽  
Grand Canonical Partition Function ◽  
Ads Black Holes ◽  
Higher Dimensional ◽  
A Charge ◽  
Grand Canonical

Abstract We revisit the microscopic description of AdS3 black holes in light of recent progress on their higher dimensional analogues. The grand canonical partition function that follows from the AdS3/CFT2 correspondence describes BPS and nearBPS black hole thermodynamics. We formulate an entropy extremization principle that accounts for both the black hole entropy and a constraint on its charges, in close analogy with asymptotically AdS black holes in higher dimensions. We are led to interpret supersymmetric black holes as ensembles of BPS microstates satisfying a charge constraint that is not respected by individual states. This interpretation provides a microscopic understanding of the hitherto mysterious charge constraints satisfied by all BPS black holes in AdS. We also develop thermodynamics and a nAttractor mechanism of AdS3 black holes in the nearBPS regime.

scholarly journals Universality of highly damped quasinormal modes for single horizon black holes

2006 ◽  
Vol 84 (6-7) ◽  
pp. 473-479
Author(s):  
R G Daghigh ◽  
G Kunstatter
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Large Class ◽  
Quasinormal Modes ◽  
Black Hole Entropy ◽  
Mode Frequency ◽  
Quasinormal Mode ◽  
Asymptotically Flat ◽  
Black Hole Temperature

It has been suggested that the highly damped quasinormal modes of black holes provide information about the microscopic quantum gravitational states underlying black-hole entropy. This interpretation requires the form of the highly damped quasinormal mode frequency to be universally of the form: [Formula: see text] = ln(l)kTBH, where l is an integer, and TBH is the black-hole temperature. We summarize the results of an analysis of the highly damped quasinormal modes for a large class of static single horizon, asymptotically flat black holes.PACS Nos.: 04.60.–m, 04.70.–s, 04.70.Dy, 04.70.Bw, 92.60.Dj

scholarly journals BLACK HOLES, SPACE-FILLING CHAINS AND RANDOM WALKS

2006 ◽  
Vol 21 (28n29) ◽  
pp. 5793-5806
Author(s):  
AXEL KRAUSE
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Random Walk ◽  
Random Walks ◽  
Black Hole Entropy ◽  
Space Filling ◽  
Four Dimensions ◽  
Higher Dimensional ◽  
Schwarzschild Radius

Many approaches to a semiclassical description of gravity lead to an integer black hole entropy. In four dimensions this implies that the Schwarzschild radius obeys a formula which describes the distance covered by a Brownian random walk. For the higher-dimensional Schwarzschild–Tangherlini black hole, its radius relates similarly to a fractional Brownian walk. We propose a possible microscopic explanation for these random walk structures based on microscopic chains which fill the interior of the black hole.

scholarly journals Islands and stretched horizon

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Yoshinori Matsuo
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hawking Radiation ◽  
Entanglement Entropy ◽  
Total System ◽  
Island Rule ◽  
Asymptotically Flat ◽  
Flat Spacetime ◽  
Ads Spacetime ◽  
Hole Geometry

Abstract Recently it was proposed that the entanglement entropy of the Hawking radiation contains the information of a region including the interior of the event horizon, which is called “island.” In studies of the entanglement entropy of the Hawking radiation, the total system in the black hole geometry is separated into the Hawking radiation and black hole. In this paper, we study the entanglement entropy of the black hole in the asymptotically flat Schwarzschild spacetime. Consistency with the island rule for the Hawking radiation implies that the information of the black hole is located in a different region than the island. We found an instability of the island in the calculation of the entanglement entropy of the region outside a surface near the horizon. This implies that the region contains all the information of the total system and the information of the black hole is localized on the surface. Thus the surface would be interpreted as the stretched horizon. This structure also resembles black holes in the AdS spacetime with an auxiliary flat spacetime, where the information of the black hole is localized at the interface between the AdS spacetime and the flat spacetime.

scholarly journals EXTREMAL BLACK HOLES AND ELEMENTARY STRING STATES

1995 ◽  
Vol 10 (28) ◽  
pp. 2081-2093 ◽  
Author(s):  
ASHOKE SEN
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Entropy ◽  
Extremal Black Hole ◽  
Coupling Constant ◽  
Left Handed ◽  
Quantum Numbers ◽  
Independent Parameters ◽  
Elementary String ◽  
Extremal Black Holes

Some of the extremal black hole solutions in string theory have the same quantum numbers as the Bogomol’nyi saturated elementary string states. We explore the possibility that these black holes can be identified with elementary string excitations. It is shown that stringy effects could correct the Bekenstein-Hawking formula for the black hole entropy in such a way that it correctly reproduces the logarithm of the density of elementary string states. In particular, this entropy has the correct dependence on three independent parameters, the mass and the left-handed charge of the black hole, and the string coupling constant.

scholarly journals Horizon Thermodynamics in D-Dimensional f(R) Black Hole

Entropy ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1246
Author(s):  
Chenrui Zhu ◽  
Rong-Jia Yang
Keyword(s):  
Black Hole ◽  
Spherically Symmetric ◽  
Higher Dimensional ◽  
Horizon Thermodynamics ◽  
Symmetric Black Hole

We consider whether the new horizon-first law works in higher-dimensional f(R) theory. We firstly obtain the general formulas to calculate the entropy and the energy of a general spherically-symmetric black hole in D-dimensional f(R) theory. For applications, we compute the entropies and the energies of some black hokes in some interesting higher-dimensional f(R) theories.

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