scholarly journals Thermodynamic approach to field equations in Lovelock gravity and f(R) gravity revisited

2014 ◽  
Vol 23 (11) ◽  
pp. 1450093 ◽  
Author(s):  
Yan-Gang Miao ◽  
Fang-Fang Yuan ◽  
Zheng-Zheng Zhang
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Field ◽  
Black Hole Thermodynamics ◽  
Thermodynamic Approach ◽  
Field Equations ◽  
Lovelock Gravity ◽  
First Law Of Thermodynamics ◽  
Charged Black Holes ◽  
Gravitational Field Equations

The first law of thermodynamics at black hole horizons is known to be obtainable from the gravitational field equations. A recent study claims that the contributions at inner horizons should be considered in order to give the conventional first law of black hole thermodynamics. Following this method, we revisit the thermodynamic aspects of field equations in the Lovelock gravity and f(R) gravity by focusing on two typical classes of charged black holes in the two theories.

scholarly journals Quasilinear reformulation of Lovelock gravity

2015 ◽  
Vol 24 (09) ◽  
pp. 1542010 ◽  
Author(s):  
Steven Willison
Keyword(s):  
Black Holes ◽  
Gravitational Field ◽  
Stability Analysis ◽  
Well Posedness ◽  
Field Equations ◽  
Lovelock Gravity ◽  
Gravitational Field Equations ◽  
The Stability ◽  
Extended Review

Here, we give an extended review of the quasilinear reformulation of the Lovelock gravitational field equations in harmonic gauge presented by Willison [Class. Quantum Grav.32 (2015) 022001]. This is important in order to establish rigorously well-posedness of the theory perturbed about certain backgrounds. The resulting system is not quasidiagonal, therefore analysis of causality is complicated in general. The conditions for the equations to be Leray hyperbolic are elucidated. The relevance to some recent results regarding the stability analysis of black holes is presented.

Can quantum black holes be (q, p)-fermions?

2017 ◽  
Vol 32 (15) ◽  
pp. 1750080 ◽  
Author(s):  
Emre Dil
Keyword(s):  
Black Holes ◽  
Gravitational Field ◽  
Fermi Gas ◽  
Einstein Equations ◽  
Quantum Corrections ◽  
Field Equations ◽  
Gravitational Field Equations ◽  
Entropic Gravity ◽  
Two Parameter

In this study, to investigate the very nature of quantum black holes, we try to relate three independent studies: (q, p)-deformed Fermi gas model, Verlinde’s entropic gravity proposal and Strominger’s quantum black holes obeying the deformed statistics. After summarizing Strominger’s extremal quantum black holes, we represent the thermostatistics of (q, p)-fermions to reach the deformed entropy of the (q, p)-deformed Fermi gas model. Since Strominger’s proposal claims that the quantum black holes obey deformed statistics, this motivates us to describe the statistics of quantum black holes with the (q, p)-deformed fermions. We then apply the Verlinde’s entropic gravity proposal to the entropy of the (q, p)-deformed Fermi gas model which gives the two-parameter deformed Einstein equations describing the gravitational field equations of the extremal quantum black holes obeying the deformed statistics. We finally relate the obtained results with the recent study on other modification of Einstein equations obtained from entropic quantum corrections in the literature.

scholarly journals Field Equations for Lovelock Gravity: An Alternative Route

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Sumanta Chakraborty
Keyword(s):  
Gravitational Field ◽  
Curvature Tensor ◽  
Thermodynamic Description ◽  
Riemann Tensor ◽  
Field Equations ◽  
Riemann Curvature Tensor ◽  
Lovelock Gravity ◽  
Warm Up ◽  
Alternative Derivation ◽  
Gravitational Field Equations

We present an alternative derivation of the gravitational field equations for Lovelock gravity starting from Newton’s law, which is closer in spirit to the thermodynamic description of gravity. As a warm up exercise, we have explicitly demonstrated that, projecting the Riemann curvature tensor appropriately and taking a cue from Poisson’s equation, Einstein’s equations immediately follow. The above derivation naturally generalizes to Lovelock gravity theories where an appropriate curvature tensor satisfying the symmetries as well as the Bianchi derivative properties of the Riemann tensor has to be used. Interestingly, in the above derivation, the thermodynamic route to gravitational field equations, suited for null hypersurfaces, emerges quiet naturally.

scholarly journals Regular black holes with $$\varLambda >0$$ and its evolution in Lovelock gravity

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
Milko Estrada ◽  
Rodrigo Aros
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Thermal Equilibrium ◽  
De Sitter ◽  
Lovelock Gravity ◽  
First Law Of Thermodynamics ◽  
Regular Black Holes ◽  
Extreme Black Hole ◽  
Hole Geometry ◽  
Gravitational Equations

Abstract In this work it is shown that the thermodynamics of regular black holes with a cosmological horizon, which are solutions of Lovelock gravity, determines that they must evolve either into a state where the black hole and cosmological horizons have reached thermal equilibrium or into an extreme black hole geometry where the black hole and cosmological horizons have merged. This differs from the behavior of Schwarzschild de Sitter geometry which evolves into a de Sitter space, the ground state of the space of solutions. This occurs due to a phase transition of the heat capacity of the black hole horizon. To perform that analysis it is shown that at each horizon a local first law of thermodynamics can be obtained from the gravitational equations.

PHYSICAL PROPERTIES OF THE THIN ACCRETION DISK OF THE TAUB-NUT BLACK HOLE

2021 ◽  
Vol 0 (1) ◽  
pp. 87-91
Author(s):  
R.M. YUSUPOVA ◽  
◽  
R.N. ZMAILOV ◽  
Keyword(s):  
Black Hole ◽  
Angular Momentum ◽  
Gravitational Field ◽  
Physical Properties ◽  
Accretion Disk ◽  
Energy Flow ◽  
Field Equations ◽  
Effective Potential Energy ◽  
Gravitational Field Equations ◽  
Vacuum Solutions

The Taub-NUT space-time metric is one of the vacuum solutions to Einstein's gravitational field equations. In this metric, the Newman-Unti-Tamburino parameter (NUT) and its effect on the physical properties of a thin accretion disk are of particular interest. In this paper, calculations are performed to determine the physical properties of a thin accretion disk around the Taub-NUT black hole based on the Page-Thorne model. The influence of the NUT parameter on the angular velocity, binding energy, angular momentum of particles, effective potential, energy flow, and temperature of the accretion disk is revealed. According to the data obtained, the temperature of the accretion disk of the Taub-NUT black hole decreases as the value of the NUT parameter increases.

scholarly journals Constructing Higher-Dimensional Exact Black Holes in Einstein-Maxwell-Scalar Theory

Universe ◽  
2020 ◽  
Vol 6 (9) ◽  
pp. 148
Author(s):  
Jianhui Qiu ◽  
Changjun Gao
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Thermodynamics ◽  
Spherically Symmetric ◽  
Dilaton Gravity ◽  
Scalar Theory ◽  
First Law Of Thermodynamics ◽  
Higher Dimensional

We construct higher-dimensional and exact black holes in Einstein-Maxwell-scalar theory. The strategy we adopted is to extend the known, static and spherically symmetric black holes in the Einstein-Maxwell dilaton gravity and Einstein-Maxwell-scalar theory. Then we investigate the black hole thermodynamics. Concretely, the generalized Smarr formula and the first law of thermodynamics are derived.

scholarly journals Mass formulae and staticity condition for dark matter charged black holes

2020 ◽  
Vol 80 (9) ◽  
Author(s):  
Marek Rogatko
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Black Hole Solution ◽  
Black Hole Thermodynamics ◽  
Stationary Black Hole ◽  
Charged Black Holes ◽  
Hidden Sector ◽  
Killing Horizon ◽  
Interior Boundary

AbstractThe Arnowitt–Deser–Misner formalism is used to derive variations of mass, angular momentum and canonical energy for Einstein–Maxwell dark matter gravity in which the auxiliary gauge field coupled via kinetic mixing term to the ordinary Maxwell one, which mimics properties of hidden sector. Inspection of the initial data for the manifold with an interior boundary, having topology of $$S^2$$ S 2 , enables us to find the generalised first law of black hole thermodynamics in the aforementioned theory. It has been revealed that the stationary black hole solution being subject to the condition of encompassing a bifurcate Killing horizon with a bifurcation sphere, which is non-rotating, must be static and has vanishing magnetic Maxwell and dark matter sector fields, on static slices of the spacetime under consideration.

Charged black holes in the infinite derivative theory of gravity

2021 ◽  
Author(s):  
Yong Xiao ◽  
Longting Zhang
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Electromagnetic Field ◽  
Electrostatic Potential ◽  
Einstein Gravity ◽  
First Law Of Thermodynamics ◽  
Charged Black Holes ◽  
Theory Of Gravity ◽  
Infinite Derivative ◽  
Black Hole Solutions

Abstract The infinite derivative theory of gravity is a generalization of Einstein gravity with many interesting properties, but the black hole solutions in this theory are still not fully understood. In the paper, we concentrate on studying the charged black holes in such a theory. Adding the electromagnetic field part to the effective action, we show how the black hole solutions around the Reissner-Nordstr{\"o}m metric can be solved perturbatively and iteratively. We further calculate the corresponding temperature, entropy and electrostatic potential of the black holes and verify the first law of thermodynamics.

scholarly journals TOPOLOGICAL BLACK HOLES IN BRANS–DICKE–MAXWELL THEORY

2009 ◽  
Vol 18 (11) ◽  
pp. 1773-1783 ◽  
Author(s):  
A. SHEYKHI ◽  
H. ALAVIRAD
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Conformal Transformation ◽  
Analytic Solution ◽  
Black Hole Thermodynamics ◽  
Thermodynamic Quantities ◽  
Dilaton Gravity ◽  
Maxwell Theory ◽  
Charged Black Holes ◽  
Euclidean Action

We derive a new analytic solution of (n + 1)-dimensional (n ≥ 4) Brans–Dicke–Maxwell theory in the presence of a potential for the scalar field, by applying a conformal transformation to the dilaton gravity theory. Such solutions describe topological charged black holes with unusual asymptotics. We obtain the conserved and thermodynamic quantities through the use of the Euclidean action method. We also study the thermodynamics of the solutions and verify that the conserved and thermodynamic quantities of the solutions satisfy the first law of black hole thermodynamics.

scholarly journals CHARGED BLACK HOLES IN VAIDYA BACKGROUNDS: HAWKING'S RADIATION

2010 ◽  
Vol 19 (04) ◽  
pp. 437-464 ◽  
Author(s):  
NG IBOHAL ◽  
L. KAPIL
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Einstein’S Field Equations ◽  
Field Equations ◽  
Naked Singularities ◽  
Charged Black Holes ◽  
Type D ◽  
Einstein's Field Equations ◽  
Vaidya Solution ◽  
The Individual

In this paper we propose a class of embedded solutions of Einstein's field equations describing nonrotating Reissner–Nordstrom–Vaidya and rotating Kerr–Newman–Vaidya black holes. The Reissner–Nordstrom–Vaidya is obtained by embedding Reissner–Nordstrom solution into the nonrotating Vaidya. Similarly, we also find the Kerr–Newman–Vaidya black hole, when Kerr–Newman embeds into the rotating Vaidya solution. The Reissner–Nordstrom–Vaidya solution is type D whereas the Kerr–Newman–Vaidya metric is algebraically special of type II by the Petrov classification of space–time. These embedded solutions can be expressed in the Kerr–Schild ansatze on different backgrounds. The energy–momentum tensors for both nonrotating as well as rotating embedded solutions satisfy the energy conservation equations which show that they are solutions of Einstein's field equations. The surface gravity, area, temperature and entropy are also presented for each embedded black hole. It is observed that the area of the embedded black holes is greater than the sum of the areas of the individual ones. By considering the charge to be a function of radial coordinates it is shown that there is a change in the masses of the variably charged black holes. If such radiation continues, the mass of the black hole will evaporate completely thereby forming "instantaneous" charged black holes and creating embedded negative mass naked singularities describing the possible the life of radiation embedded black holes during their continuous radiation processes.

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