scholarly journals Distorted vacuum black holes in the canonical ensemble

2019 ◽  
Vol 34 (07n08) ◽  
pp. 1950060
Author(s):  
O. B. Zaslavskii
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Coordinate System ◽  
Uniqueness Theorem ◽  
Canonical Ensemble ◽  
Finite Size ◽  
Horizon Area ◽  
Spatial Symmetry ◽  
Flat Spacetime ◽  
The Uniqueness Theorem

We consider a vacuum static spacetime in a finite size cavity. On the boundary, we specify a metric and a finite constant local temperature [Formula: see text]. No spherical or any other spatial symmetry is assumed. We show that (i) inside a cavity, only a black hole or flat spacetime are possible, whereas a curved horizonless regular spacetime is excluded, (ii) in the limit when the horizon area shrinks, the Hawking temperature diverges, (iii) for the existence of a black hole, [Formula: see text] should be high enough. When [Formula: see text], a black hole phase is favorable thermodynamically. Our consideration essentially uses the coordinate system introduced by Israel in his famous proof of the uniqueness theorem.

scholarly journals HORIZON MASS THEOREM

2005 ◽  
Vol 14 (12) ◽  
pp. 2219-2225 ◽  
Author(s):  
YUAN K. HA
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Uniqueness Theorem ◽  
Hawking Radiation ◽  
General Theorem ◽  
Positive Energy ◽  
Singularity Theorem ◽  
Area Theorem ◽  
Classical Black Holes ◽  
The Uniqueness Theorem

A new theorem for black holes is found. It is called the horizon mass theorem. The horizon mass is the mass which cannot escape from the horizon of a black hole. For all black holes, neutral, charged or rotating, the horizon mass is always twice the irreducible mass observed at infinity. Previous theorems on black holes are: (i) the singularity theorem, (ii) the area theorem, (iii) the uniqueness theorem, (iv) the positive energy theorem. The horizon mass theorem is possibly the last general theorem for classical black holes. It is crucial for understanding Hawking radiation and for investigating processes occurring near the horizon.

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 Distributions of extremal black holes in Calabi-Yau compactifications

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
George Hulsey ◽  
Shamit Kachru ◽  
Sungyeon Yang ◽  
Max Zimet
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Moduli Space ◽  
Black Hole Horizon ◽  
Extremal Black Hole ◽  
Vector Multiplet ◽  
Horizon Area ◽  
Extremal Black Holes

Abstract We study non-supersymmetric extremal black hole excitations of 4d $$ \mathcal{N} $$ N = 2 supersymmetric string vacua arising from compactification on Calabi-Yau threefolds. The values of the (vector multiplet) moduli at the black hole horizon are governed by the attractor mechanism. This raises natural questions, such as “what is the distribution of attractor points on moduli space?” and “how many attractor black holes are there with horizon area up to a certain size?” We employ tools developed by Denef and Douglas [1] to answer these questions.

scholarly journals ECO-spotting: looking for extremely compact objects with bosonic fields

2021 ◽  
Author(s):  
Vitor Cardoso ◽  
Caio F. B. Macedo ◽  
Kei-ichi Maeda ◽  
Hirotada Okawa
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Compact Objects ◽  
Spherically Symmetric ◽  
Initial Value ◽  
Flat Spacetime ◽  
The Universe ◽  
Well Posed ◽  
Black Hole Solutions ◽  
Hairy Black Hole

Abstract Black holes are thought to describe the geometry of massive, dark compact objects in the universe. To further support and quantify this long-held belief requires knowledge of possible, if exotic alternatives. Here, we wish to understand how compact can self-gravitating solutions be. We discuss theories with a well-posed initial value problem, consisting in either a single self-interacting scalar, vector or both. We focus on spherically symmetric solutions, investigating the influence of self-interacting potentials into the compactness of the solutions, in particular those that allow for flat-spacetime solutions. We are able to connect such stars to hairy black hole solutions, which emerge as a zero-mass black hole. We show that such stars can have light rings, but their compactness is never parametrically close to that of black holes. The challenge of finding black hole mimickers to investigate full numerical-relativity binary setups remains open.

scholarly journals Tunnelling radiation of charged particles from a Hořava–Lifshitz gravity black hole

2019 ◽  
Vol 59 (1) ◽  
Author(s):  
Gu-Qiang Li ◽  
Yan-Yi Ou ◽  
Ze-Tao Lin
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Emission Spectrum ◽  
Hawking Radiation ◽  
Emission Rate ◽  
Charged Particles ◽  
Logarithmic Term ◽  
Unitary Theory ◽  
Horizon Area ◽  
First Law Of Thermodynamics

The Hawking radiation of charged particles from black holes in the Hořava–Lifshitz (HL) gravity is investigated by using the Parikh–Wilczek (PW) method, and the emission rate is calculated. The emission spectrum is not purely thermal and is consistent with an underlying unitary theory. Some other characteristics exist for a HL gravity black hole. Assuming the conventional tunnelling rate associated with the change of entropy, the entropy of the HL gravity black hole is obtained. The entropy is not proportional to the horizon area because a logarithmic term exists. However, it complies with the first law of thermodynamics and is in accord with earlier results.

Black holes in the theory of the dynamic medium of reference

2020 ◽  
Vol 33 (4) ◽  
pp. 395-399
Author(s):  
Olivier Pignard
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Coordinate System ◽  
Free Fall ◽  
Local Measurement ◽  
Speed Of Light ◽  
Material Particle ◽  
Propagation Medium

The aim of this article is to apply the theory of the dynamic medium of reference [O. Pignard, Phys. Essays 32, 422 (2019)] to black holes and to find all the results of general relativity concerning black holes without rotation and without load. Among the most important results to which this article leads, we can mention: (1) The speed of the flux of the medium is greater than the speed of light inside the horizon of a black hole or even much greater than the speed of light at a distance from the center of the black hole much less than the radius of Schwarzschild. (2) In the hybrid coordinate system (drSchwarzschild, dtfree fall), the speed of light is established simply in relation to its propagation medium. (3) A photon emitted at an infinite distance from the black hole with speed c 0 arrives near the horizon of the black hole with a real speed zero. And yet the local measurement of the speed of the photon carried out with a material clock and a material ruler remains c 0. (4) Study of the possible orbits of a material particle around a black hole and the possibility of orbits of a photon around a black hole.

scholarly journals Slicing black hole spacetimes

2015 ◽  
Vol 12 (07) ◽  
pp. 1550070 ◽  
Author(s):  
Donato Bini ◽  
Eduardo Bittencourt ◽  
Andrea Geralico ◽  
Robert T. Jantzen
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
General Framework ◽  
The Other ◽  
Initial Value ◽  
Black Hole Spacetimes ◽  
Flat Spacetime ◽  
The World ◽  
Stationary Spacetimes ◽  
Associated Family

A general framework is developed to investigate the properties of useful choices of stationary spacelike slicings of stationary spacetimes whose congruences of timelike orthogonal trajectories are interpreted as the world lines of an associated family of observers, the kinematical properties of which in turn may be used to geometrically characterize the original slicings. On the other hand, properties of the slicings themselves can directly characterize their utility motivated instead by other considerations like the initial value and evolution problems in the 3-plus-1 approach to general relativity. An attempt is made to categorize the various slicing conditions or "time gauges" used in the literature for the most familiar stationary spacetimes: black holes and their flat spacetime limit.

scholarly journals Thermal fluctuations and correlations among hairs of a stable quantum black hole: Some examples

2018 ◽  
Vol 33 (33) ◽  
pp. 1850190 ◽  
Author(s):  
Aloke Kumar Sinha
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Electric Charge ◽  
Magnetic Charge ◽  
Thermal Fluctuations ◽  
Horizon Area ◽  
Dimensional Spacetime ◽  
Newman Black Hole ◽  
Area Limit

We have already derived the criteria for thermal stability of charged rotating quantum black holes, for horizon areas that are large relative to the Planck area. The derivation is done by using results of loop quantum gravity and equilibrium statistical mechanics of the grand canonical ensemble. We have also showed that in four-dimensional spacetime, quantum AdS Kerr–Newman black hole and asymptotically AdS dyonic black hole with electric and magnetic charge are thermally stable within certain range of its parameters. In this paper, the expectation values of fluctuations and correlations among horizon area, electric charge and angular momentum (magnetic charge) of these black holes are calculated within their range of stability. Interestingly, it is found that leading order fluctuations of electric charge and angular momentum (magnetic charge), in large horizon area limit, are independent of the values of electric charge and angular momentum (magnetic charge) at equilibrium.

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