scholarly journals BLACK HOLE THERMODYNAMICS FROM THE POINT OF VIEW OF SUPERSTRING THEORY

2000 ◽  
Vol 15 (01) ◽  
pp. 1-44 ◽  
Author(s):  
E. T. AKHMEDOV
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Recent Progress ◽  
Black Hole Entropy ◽  
Black Hole Thermodynamics ◽  
Point Of View ◽  
Superstring Theory ◽  
Black Hole Evaporation ◽  
Statistical Explanation

In this review we try to give a pedagogical introduction to the recent progress in the resolution of old problems of black hole thermodynamics within superstring theory. We start with a brief description of classical black hole dynamics. Then, follow with the consideration of general properties of supersymmetric black holes. We conclude with the review of the statistical explanation of the black hole entropy and string theory description of the black hole evaporation.

BLACK HOLE ENTROPY IN STRING THEORY: GOING BEYOND BEKENSTEIN AND HAWKING

2006 ◽  
Vol 15 (10) ◽  
pp. 1561-1572 ◽  
Author(s):  
ATISH DABHOLKAR
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Recent Progress ◽  
Black Hole Entropy ◽  
Quantum Corrections ◽  
Corrected Entropy

In this talk I summarize some recent progress in string theory in understanding the entropy of a class of black holes including corrections to the Bekenstein–Hawking formula. The quantum corrected entropy is in precise numerical agreement with the logarithm of the number of microstates once quantum corrections are correctly taken into account.

scholarly journals Ramanujan's influence on string theory, black holes and moonshine

2019 ◽  
Vol 378 (2163) ◽  
pp. 20180440 ◽  
Author(s):  
Jeffrey A. Harvey
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Modular Forms ◽  
Black Hole Entropy ◽  
Additional Material ◽  
Mock Modular Forms

Ramanujan influenced many areas of mathematics, but his work on q -series, on the growth of coefficients of modular forms and on mock modular forms stands out for its depth and breadth of applications. I will give a brief overview of how this part of Ramanujan's work has influenced physics with an emphasis on applications to string theory, counting of black hole states and moonshine. This paper contains the material from my presentation at the meeting celebrating the centenary of Ramanujan's election as FRS and adds some additional material on black hole entropy and the AdS/CFT correspondence. This article is part of a discussion meeting issue ‘Srinivasa Ramanujan: in celebration of the centenary of his election as FRS’.

EXOTIC BRANES AND BLACK HOLE MICROSTATES

2013 ◽  
Vol 21 ◽  
pp. 77-91 ◽  
Author(s):  
MASAKI SHIGEMORI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Recent Progress ◽  
Codimension Two ◽  
Multi Stage ◽  
Six Dimensions

Besides ordinary branes such as D-branes, string theory is known to contain exotic branes which are related to ordinary branes by U-duality. Exotic branes are codimension-two objects and have non-trivial U-duality monodromies around them. This means that they are intrinsically non-geometric. Even if one starts with a system only with ordinary branes, exotic branes can be spontaneously generated by the supertube effect. We argue that, if one puts together more than two mutually supersymmetric branes, then, by a multi-stage supertube effect, the system will polarize into an exotic brane extending along an arbitrary surface, dubbed as the superstratum. We conjecture that, black holes in string theory, which are constructed by combining multiple ordinary branes, necessarily include exotic superstrata as their microscopic ingredients. We review the argument for the existence of superstrata and the recent progress toward constructing examples of superstrata in the framework of supergravity in six dimensions.

scholarly journals Black hole event horizons — Teleology and predictivity

2017 ◽  
Vol 32 (34) ◽  
pp. 1750186
Author(s):  
Swastik Bhattacharya ◽  
S. Shankaranarayanan
Keyword(s):  
Boundary Condition ◽  
Black Holes ◽  
Black Hole ◽  
Black Hole Thermodynamics ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Black Hole Evaporation ◽  
Spacetime Manifold ◽  
Statistical Mechanical ◽  
Late Stages

General Relativity predicts the existence of black holes. Access to the complete spacetime manifold is required to describe the black hole. This feature necessitates that black hole dynamics is specified by future or teleological boundary condition. Here, we demonstrate that the statistical mechanical description of black holes, the raison d’être behind the existence of black hole thermodynamics, requires teleological boundary condition. Within the fluid–gravity paradigm — Einstein’s equations when projected on spacetime horizons resemble Navier–Stokes equation of a fluid — we show that the specific heat and the coefficient of bulk viscosity of the horizon fluid are negative only if the teleological boundary condition is taken into account. We argue that in a quantum theory of gravity, the future boundary condition plays a crucial role. We briefly discuss the possible implications of this at late stages of black hole evaporation.

scholarly journals FROM QUBITS TO BLACK HOLES: ENTROPY, ENTANGLEMENT AND ALL THAT

2005 ◽  
Vol 14 (12) ◽  
pp. 2307-2314 ◽  
Author(s):  
DANIEL R. TERNO
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Loop Quantum Gravity ◽  
Black Hole Entropy ◽  
Logarithmic Correction ◽  
Evaporation Process ◽  
Spin Networks ◽  
Black Hole Evaporation ◽  
Single Qubit

Entropy plays a crucial role in the characterization of information and entanglement, but it is not a scalar quantity and for many systems it is different for different relativistic observers. We discuss two examples: entropy of a single qubit and renormalized entropy as given by a uniformly accelerated observer. Loop quantum gravity predicts the Bekenstein–Hawking term for black hole entropy and the logarithmic correction to it. The latter originates in the entanglement between the pieces of spin networks that describe black hole horizon. Entanglement between gravity and matter may restore the unitarity in the black hole evaporation process. If the collapsing matter is assumed to be initially in a pure state, then entropy of the Hawking radiation is exactly the created entanglement between matter and gravity.

ASPECTS OF NEAR-HORIZON CONFORMAL SYMMETRY

2005 ◽  
Vol 20 (11) ◽  
pp. 2485-2489 ◽  
Author(s):  
KUMAR S. GUPTA
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Conformal Symmetry ◽  
Black Hole Entropy ◽  
Point Of View ◽  
Algebraic Point

We analyze the features of the near-horizon conformal symmetry of black holes from an algebraic point of view. The implications of such a symmetry for black hole entropy and decay are also discussed.

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 String analog of Reissner–Nordström black holes cannot be overcharged

2019 ◽  
Vol 34 (30) ◽  
pp. 1950248 ◽  
Author(s):  
Koray Düztaş ◽  
Mubasher Jamil
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Black Hole Thermodynamics ◽  
Drop Out ◽  
Charged Black Holes ◽  
The Third ◽  
Test Particles ◽  
Third Law ◽  
Extremal Black Holes

In this work, we attempt to overcharge extremal and nearly extremal charged black holes in string theory, known as the Garfinkle–Horowitz–Strominger solution. We first show that extremal black holes cannot be overcharged analogous to the case of Reissner–Nordström (RN) black holes. Contrary to their analog in general relativity, nearly extremal black holes can neither be overcharged beyond extremality, nor can they be driven to extremality by the interaction with test particles. Therefore, the analysis in this work also implies that the third law of black hole thermodynamics holds for the relevant charged black holes in string theory perturbed by test particles. This can be interpreted as a stronger version of the third law since one can drop out the continuity proviso for the relevant process.

scholarly journals Dilaton black hole entropy from entropy function formalism

2019 ◽  
Vol 79 (9) ◽  
Author(s):  
Komeil Babaei Velni ◽  
Ali Jalali ◽  
Bahareh Khoshdelan
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Black Hole Entropy ◽  
Entropy Function ◽  
Extremum Point ◽  
Function Formalism ◽  
Dilaton Black Hole

Abstract It has been shown that the entropy function formalism is an efficient way to calculate the entropy of black holes in string theory. We check this formalism for the extremal charged dilaton black hole. We find the general four-derivative correction on the black hole entropy from the value of the entropy function at its extremum point.

scholarly journals Black holes and Boyle's law — The thermodynamics of the cosmological constant

2015 ◽  
Vol 30 (03n04) ◽  
pp. 1540002 ◽  
Author(s):  
Brian P. Dolan
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Cosmological Constant ◽  
Recent Progress ◽  
Black Hole Thermodynamics ◽  
Thermodynamic Variable ◽  
Conjugate Variable ◽  
Boyle’S Law

When the cosmological constant, Λ, is interpreted as a thermodynamic variable in the study of black hole thermodynamics a very rich structure emerges. It is natural to interpret Λ as a pressure and define the thermodynamically conjugate variable to be the thermodynamic volume of the black hole (which need not bear any relation to the geometric volume). Recent progress in this new direction for black hole thermodynamics is reviewed.

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