scholarly journals Absence of static, spherically symmetric black hole solutions for Einstein–Dirac–Yang/Mills equations with complete fermion shells

2000 ◽  
Vol 4 (6) ◽  
pp. 1231-1257 ◽  
Author(s):  
Felix Finster ◽  
Joel Smoller ◽  
Shing-Tung Yau
Keyword(s):  
Black Hole ◽  
Spherically Symmetric ◽  
Yang Mills ◽  
Symmetric Black Hole ◽  
Black Hole Solutions

Spherically symmetric black hole solution in mimetic gravity and anti-evaporation

2018 ◽  
Vol 15 (09) ◽  
pp. 1850154 ◽  
Author(s):  
G. G. L. Nashed
Keyword(s):  
Black Hole ◽  
Black Hole Solution ◽  
Spherically Symmetric ◽  
Mimetic Theory ◽  
Event Horizons ◽  
Flat Spacetime ◽  
Symmetric Black Hole ◽  
The Stability ◽  
Mimetic Gravity ◽  
Black Hole Solutions

In this paper, we study the mimetic theory and derive a new spherically symmetric black hole solution. The asymptotic behavior of this solution behaves as a flat spacetime. This black hole is characterized by the fact that it has different components of [Formula: see text] and [Formula: see text]. Nevertheless, both of these components have a coinciding Killing and event horizons. Furthermore, this black hole has curvature singularities which are stronger than those of the known black hole solutions in general relativity. This feature can be shown by calculating some invariants of curvature. We study the stability of the perturbation and the related anti-evaporation of the Nariai spacetime.

scholarly journals Black hole thermodynamics and heat engines in conformal gravity

2017 ◽  
Vol 26 (13) ◽  
pp. 1750151 ◽  
Author(s):  
Hao Xu ◽  
Yuan Sun ◽  
Liu Zhao
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Thermodynamics ◽  
Spherically Symmetric ◽  
Conformal Gravity ◽  
Extended Phase ◽  
Heat Engines ◽  
Equation Of States ◽  
Symmetric Black Hole ◽  
Black Hole Solutions

The extended phase-space thermodynamics and heat engines for static spherically symmetric black hole solutions of four-dimensional conformal gravity are studied in detail. It is argued that the equation of states (EOS) for such black holes is always branched, any continuous thermodynamical process cannot drive the system from one branch of the EOS into another branch. Meanwhile, the thermodynamical volume is bounded from above, making the black holes always super-entropic in one branch and may also be super-entropic in another branch in certain range of the temperature. The Carnot and Stirling heat engines associated to such black holes are shown to be distinct from each other. For rectangular heat engines, the efficiency always approaches zero when the rectangle becomes extremely narrow, and given the highest and lowest working temperatures fixed, there is always a maximum for the efficiency of such engines.

Thermodynamics of apparent horizons under conformal and Kerr–Schild maps

2015 ◽  
Vol 93 (9) ◽  
pp. 963-965
Author(s):  
Valerio Faraoni ◽  
Vincenzo Vitagliano
Keyword(s):  
Black Hole ◽  
Internal Energy ◽  
Spherically Symmetric ◽  
Apparent Horizons ◽  
Symmetric Black Hole ◽  
Black Hole Solutions

We derive the transformation properties of the internal energy and Kodama temperature of dynamical (spherically symmetric) black hole solutions generated through spacetime mappings. We use the Sultana-Dyer black hole and the Reissner–Nordström solution to provide prototypical examples testing our transformation formulae.

scholarly journals Peculiar five-dimensional black holes

2019 ◽  
Vol 17 (1, spec.issue) ◽  
pp. 69-78
Author(s):  
Dejan Simic
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Semiclassical Approximation ◽  
Three Dimensions ◽  
Spherically Symmetric ◽  
Btz Black Hole ◽  
Lovelock Gravity ◽  
Zero Entropy ◽  
Symmetric Black Hole ◽  
Black Hole Solutions

In this article, we review two black hole solutions to the five-dimensional Lovelock gravity. These solutions are characterized by the non-vanishing torsion and the peculiar property that all their conserved charges vanish. The first solution is a spherically symmetric black hole with torsion, which also has zero entropy in the semiclassical approximation. The second solution is a black ring, which is the five-dimensional uplift of the BTZ black hole with torsion in three dimensions.

scholarly journals Thermodynamics of spherically symmetric black holes in scale-dependent gravity

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
P. Bargueño ◽  
J. A. Miralles ◽  
J. A. Pons
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Spatial Variation ◽  
Gravitational Constant ◽  
Spherically Symmetric ◽  
Equilibrium Thermodynamics ◽  
First Law Of Thermodynamics ◽  
Symmetric Black Hole ◽  
Black Hole Solutions

AbstractIn this work we extend the first law of thermodynamics to spherically symmetric black hole solutions in the context of scale-dependent gravity. After deriving generalized expressions for both the entropy and energy due to the spatial variation of the gravitational constant we analize, by pointing out some relations between scale-dependent and f(R) theories, whether or not the former can be described using equilibrium thermodynamics.

scholarly journals Black Holes with Short Hair

1997 ◽  
Vol 06 (05) ◽  
pp. 563-573 ◽  
Author(s):  
J. David Brown ◽  
Viqar Husain
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Einstein Gravity ◽  
Spherically Symmetric ◽  
Short Hair ◽  
Anisotropic Matter ◽  
Symmetric Black Hole ◽  
Black Hole Solutions

We present spherically symmetric black hole solutions for Einstein gravity coupled to anisotropic matter. We show that these black holes have arbitrarily short hair, and argue for stability by showing that they can arise from dynamical collapse. We also show that a recent "no short hair" theorem does not apply to these solutions.

scholarly journals New spherically symmetric solutions in the Einstein–Yang–Mills–Higgs model

2010 ◽  
Vol 88 (3) ◽  
pp. 189-200 ◽  
Author(s):  
Junji Jia
Keyword(s):  
Black Hole ◽  
Boundary Conditions ◽  
Parameter Space ◽  
Numerical Solutions ◽  
Classical Solutions ◽  
Spherically Symmetric ◽  
Regular Solutions ◽  
Asymptotically Flat ◽  
Yang Mills ◽  
Black Hole Solutions

We study classical solutions in the SU(2) Einstein–Yang–Mills–Higgs theory. The spherically symmetric ansatz for all fields are given, and the equations of motion are derived as a system of ordinary differential equations. The asymptotics and the boundary conditions at the space origin for regular solutions and at the event horizon for black hole solutions are studied. Using the shooting method, we found numerical solutions to the theory. For regular solutions, we find two new sets of asymptotically flat solutions. Each of these sets contains continua of solutions in the parameter space spanned by the shooting parameters. The solutions bifurcate along these parameter curves, and the bifurcations are argued to be due to the internal structure of the model. Both sets of the solutions are asymptotically flat, but one is exponentially so and the other is so with oscillations. For black holes, a new set of boundary conditions is studied, and it is found that there also exists a continuum of black hole solutions in parameter space and similar bifurcation behavior is also present to these solutions. The SU(2) charges of these solutions are found to be zero, and these solutions are proven to be unstable.

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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