scholarly journals EXTREME DYONIC BLACK HOLES IN STRING THEORY

1996 ◽  
Vol 11 (09) ◽  
pp. 689-713 ◽  
Author(s):  
A.A. TSEYTLIN
Keyword(s):  
Black Holes ◽  
String Theory ◽  
Short Distance ◽  
Black Hole Entropy ◽  
Universal Relation ◽  
Type Ii ◽  
Statistical Entropy ◽  
Five Dimensions ◽  
Compact Dimension ◽  
Lower Dimensional

Supersymmetric extreme dyonic black holes of toroidally compactified heterotic or type-II string theory can be viewed as lower-dimensional images of solitonic strings wound around a compact dimension. We consider conformal sigma models which describe string configurations corresponding to various extreme dyonic black holes in four and five dimensions. These conformal models have regular short-distance region equivalent to a WZW theory with level proportional to magnetic charges. Arguments are presented suggesting a universal relation between the black hole entropy (area) and the statistical entropy of BPS-saturated oscillation states of solitonic string.

scholarly journals BLACK HOLE ENTROPY BY THE BRICK-WALL METHOD IN FOUR AND FIVE DIMENSIONS WITH U(1) CHARGES

2001 ◽  
Vol 16 (39) ◽  
pp. 2495-2503 ◽  
Author(s):  
ELCIO ABDALLA ◽  
L. ALEJANDRO CORREA-BORBONET
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Scalar Field ◽  
Black Hole Entropy ◽  
Brick Wall ◽  
Statistical Entropy ◽  
Five Dimensions ◽  
Entropy Formula ◽  
Wall Method

Using the brick-wall method we compute the statistical entropy of a scalar field in a nontrivial background, in two different cases. These backgrounds are generated by four- and five-dimensional black holes with four and three U(1) charges respectively. The Bekenstein entropy formula is generally obeyed, but corrections are discussed in the latter case.

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 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’.

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 Holographic Cavalieri principle as a universal relation between holographic complexity and holographic entanglement entropy

2018 ◽  
Vol 27 (09) ◽  
pp. 1850103 ◽  
Author(s):  
Davood Momeni ◽  
Mir Faizal ◽  
Ratbay Myrzakulov
Keyword(s):  
Black Holes ◽  
String Theory ◽  
Entanglement Entropy ◽  
Circular Disk ◽  
Universal Relation ◽  
De Sitter ◽  
Cavalieri Principle ◽  
Holographic Entanglement Entropy ◽  
Type Iib String Theory

In this paper, we will propose a universal relation between the holographic complexity (dual to a volume in AdS) and the holographic entanglement entropy (dual to an area in anti-de Sitter (AdS)). We will explicitly demonstrate that our conjuncture holds for all metrics asymptotic to [Formula: see text], and then argue that such a relation should hold in general due to the AdS version of the Cavalieri principle. We will demonstrate that it holds for Janus solution, which have been recently been obtained in type IIB string theory. We will also show that this conjecture holds for a circular disk. This conjecture will be used to show that the proposal that the complexity equals action and the proposal that the complexity equals volume can represent the same physics. Thus, using this conjecture, we will show that the black holes are fastest computers, using the proposal that complexity equals volume.

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.

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 Hurwitz class numbers

2017 ◽  
Vol 26 (12) ◽  
pp. 1742003 ◽  
Author(s):  
Shamit Kachru ◽  
Arnav Tripathy
Keyword(s):  
Black Holes ◽  
Number Theory ◽  
String Theory ◽  
Modular Form ◽  
Counting Function ◽  
Class Numbers ◽  
Type Ii ◽  
Mock Modular Form

We define a natural counting function for BPS black holes in [Formula: see text] compactification of type II string theory, and observe that it is given by a weight 3/2 mock modular form discovered by Zagier. This hints at tantalizing relations connecting black holes, string theory, and number theory.

scholarly journals Effects of the external string cloud on the Van der Waals-like behavior and efficiency of AdS-Schwarzschild black holes in massive gravity

2020 ◽  
Vol 35 (24) ◽  
pp. 2050203
Author(s):  
M. Ghanaatian ◽  
Mehdi Sadeghi ◽  
Hadi Ranjbari ◽  
Gh. Forozani
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Black Hole ◽  
Van Der Waals ◽  
Black Hole Entropy ◽  
Five Dimensions ◽  
Four Dimensions ◽  
Heat Engines ◽  
Cloud Parameter ◽  
Extremal Black Holes

In this paper, we study AdS-Schwarzschild black holes in four and five dimensions in dRGT minimally coupled to a cloud of strings. It is observed that the entropy of the string cloud and massive terms does not affect the black hole entropy. The observations about four dimensions indicate that the massive term in the presence of external string cloud cannot exhibit Van der Waals-like behavior for AdS-Schwarzschild black holes and, therefore there is only the Hawking–Page phase transition. In contrast, in five dimensions, the graviton mass modifies this behavior through the third massive term, so that a critical behavior and second-order phase transition is deduced. Also, the Joule–Thomson effect is not observed. The black hole stability conditions are also studied in four and five dimensions and a critical value for the string cloud parameter is presented. In five dimensions a degeneracy between states for extremal black holes is investigated. After studying black holes as thermodynamic systems, we consider such systems as heat engines, and finally the efficiency of them is calculated.

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