scholarly journals On thermodynamics of 2D black holes in brane inflationary potentials

2014 ◽  
Vol 11 (05) ◽  
pp. 1450047 ◽  
Author(s):  
A. Belhaj ◽  
M. Chabab ◽  
H. El Moumni ◽  
M. B. Sedra ◽  
A. Segui
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Solution ◽  
Brane World ◽  
Two Dimensional ◽  
Dilaton Gravity ◽  
De Sitter ◽  
Asymptotic Behaviors ◽  
Dimensional Black Hole ◽  
Hole Geometry

Inspired from the inflation brane world cosmology, we study the thermodynamics of a black hole solution in two-dimensional dilaton gravity with an arctangent potential background. We first derive the two-dimensional black hole geometry, then we examine its asymptotic behaviors. More precisely, we find that such behaviors exhibit properties appearing in some known cases including the anti-de Sitter and the Schwarzschild black holes. Using the complex path method, we compute the Hawking radiation. The entropy function can be related to the value of the potential at the horizon.

scholarly journals TACHYON EFFECTS ON THE TWO-DIMENSIONAL BLACK HOLE GEOMETRY

1995 ◽  
Vol 10 (18) ◽  
pp. 1277-1286 ◽  
Author(s):  
G.A. DIAMANDIS ◽  
B.C. GEORGALAS ◽  
E. PAPANTONOPOULOS
Keyword(s):  
Exact Solution ◽  
Black Hole ◽  
Black Hole Solution ◽  
Equations Of Motion ◽  
Tree Level ◽  
Two Dimensional ◽  
Full System ◽  
Dimensional Black Hole ◽  
Hole Geometry ◽  
Hole Structure

We study solutions of the tree level string effective action in the presence of the tachyon mode. In the case of static fields we find numerically that the full system has a black hole solution with the tachyon regular at the horizon. We also find a nonstatic exact solution of the equations of motion having a black hole structure with a past singularity.

scholarly journals Uptunneling to de Sitter

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Mehrdad Mirbabayi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
False Vacuum ◽  
De Sitter ◽  
Dimensional Theory ◽  
Hole Geometry ◽  
Horizon Geometry ◽  
Two Sides ◽  
Extremal Black Holes

Abstract We propose a Euclidean preparation of an asymptotically AdS2 spacetime that contains an inflating dS2 bubble. The setup can be embedded in a four dimensional theory with a Minkowski vacuum and a false vacuum. AdS2 approximates the near horizon geometry of a two-sided near-extremal Reissner-Nordström black hole, and the two sides can connect to the same Minkowski asymptotics to form a topologically nontrivial worm- hole geometry. Likewise, in the false vacuum the near-horizon geometry of near-extremal black holes is approximately dS2 times 2-sphere. We interpret the Euclidean solution as describing the decay of an excitation inside the wormhole to a false vacuum bubble. The result is an inflating region inside a non-traversable asymptotically Minkowski wormhole.

scholarly journals Islands in linear dilaton black holes

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Georgios K. Karananas ◽  
Alex Kehagias ◽  
John Taskas
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Entanglement Entropy ◽  
Von Neumann Entropy ◽  
Two Dimensional ◽  
Extremal Case ◽  
Von Neumann ◽  
Dimensional Black Hole ◽  
Linear Dilaton ◽  
Linear Dilaton Black Hole

Abstract We derive a novel four-dimensional black hole with planar horizon that asymptotes to the linear dilaton background. The usual growth of its entanglement entropy before Page’s time is established. After that, emergent islands modify to a large extent the entropy, which becomes finite and is saturated by its Bekenstein-Hawking value in accordance with the finiteness of the von Neumann entropy of eternal black holes. We demonstrate that viewed from the string frame, our solution is the two-dimensional Witten black hole with two additional free bosons. We generalize our findings by considering a general class of linear dilaton black hole solutions at a generic point along the σ-model renormalization group (RG) equations. For those, we observe that the entanglement entropy is “running” i.e. it is changing along the RG flow with respect to the two-dimensional worldsheet length scale. At any fixed moment before Page’s time the aforementioned entropy increases towards the infrared (IR) domain, whereas the presence of islands leads the running entropy to decrease towards the IR at later times. Finally, we present a four-dimensional charged black hole that asymptotes to the linear dilaton background as well. We compute the associated entanglement entropy for the extremal case and we find that an island is needed in order for it to follow the Page curve.

scholarly journals ON KALUZA–KLEIN SPACE–TIME IN EINSTEIN–GAUSS–BONNET GRAVITY

2009 ◽  
Vol 18 (04) ◽  
pp. 599-611 ◽  
Author(s):  
ALFRED MOLINA ◽  
NARESH DADHICH
Keyword(s):  
Black Hole ◽  
Black Hole Solution ◽  
Dimensional Space ◽  
Space Time ◽  
Two Dimensional ◽  
Bonnet Gravity ◽  
Space Of Constant Curvature ◽  
Dimensional Black Hole ◽  
Dimensional Space Time ◽  
Kaluza Klein

By considering the product of the usual four-dimensional space–time with two dimensional space of constant curvature, an interesting black hole solution has recently been found for Einstein–Gauss–Bonnet gravity. It turns out that this as well as all others could easily be made to radiate Vaidya null dust. However, there exists no Kerr analog in this setting. To get the physical feel of the four-dimensional black hole space–times, we study asymptotic behavior of stresses at the two ends, r → 0 and r → ∞.

scholarly journals Fuzzy dark matter black holes and droplets

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
D. Batic ◽  
D. Asem Abuhejleh ◽  
M. Nowakowski
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Black Hole Solution ◽  
Mass Parameter ◽  
Radial Pressure ◽  
Momentum Tensor ◽  
Anisotropic Fluid ◽  
De Sitter ◽  
Hole Model

AbstractWe consider the possibility of having Dark Matter (DM) black holes motivated by the Einasto density profile. This generalizes both the noncommutative mini black hole model and allows DM to enter as the matter constituent which makes up the black hole. We show that it is possible to construct a black hole solution for each value of the Einasto index and for different values of the mass parameter, provided that the we work with the energy–momentum tensor of an anisotropic fluid. In particular, we achieve that by first considering the equation of state (EOS) $$p_r=-\rho $$ p r = - ρ . It turns out that the corresponding black hole solution exhibits a horizon structure similar to that of a Reissner–Nordström black hole and the central singularity is replaced by a regular de Sitter core. We also show that if the previous EOS is replaced by a nonlocal one, it is possible to construct a self-gravitating fuzzy DM droplet but also in this case, the radial pressure is negative. Finally, we contemplate scenarios of different dark matter black holes with moderate mass values which could have formed in galaxies. In particular, we probe the possibility whether such black holes could also be the central galactic objects.

scholarly journals Probing correlation between photon orbits and phase structure of charged AdS black hole in massive gravity background

2019 ◽  
Vol 34 (35) ◽  
pp. 1950231 ◽  
Author(s):  
M. Chabab ◽  
H. El Moumni ◽  
S. Iraoui ◽  
K. Masmar
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Black Hole ◽  
Phase Structure ◽  
Black Hole Solution ◽  
Massive Gravity ◽  
Direct Link ◽  
De Sitter ◽  
Thermodynamic Phase ◽  
The Impact

The phase structure of charged anti-de Sitter black hole in massive gravity is investigated using the unstable circular photon orbits formalism, concretely we establish a direct link between the null geodesics and the critical behavior thermodynamic of such black hole solution. Our analysis reveals that the radius and the impact parameter corresponding to the unstable circular orbits can be used to probe the thermodynamic phase structure. We also show that the latter are key quantities to characterize the order of Van der Waals-like phase transition. Namely, we found a critical exponent around [Formula: see text]. All these results support further that the photon trajectories can be used as a useful and crucial tool to probe the thermodynamic black holes criticality.

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.

Further selected solutions

2020 ◽  
pp. 200-258
Author(s):  
Piotr T. Chruściel
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
De Sitter ◽  
Stationary Black Hole ◽  
Static Vacuum ◽  
Black Hole Spacetimes ◽  
Wide Range ◽  
Dimensional Black Hole ◽  
Horizon Topology ◽  
Basic Features

In previous chapters we presented the key notions associated with stationary black-hole spacetimes, as well as the minimal set of metrics needed to illustrate the basic features of the world of black holes. In this chapter we present some further black holes, selected because of their physical and mathematical interest. We start, in Section 5.1, with the Kerr–de Sitter/anti-de Sitter metrics, the cosmological counterparts of the Kerr metrics. Section 5.2 contains a description of the Kerr–Newman–de Sitter/anti-de Sitter metrics, which are the charged relatives of the metrics presented in Section 5.1. In Section 5.3 we analyse in detail the global structure of the Emparan–Reall ‘black rings’: these are five-dimensional black-hole spacetimes with R × S 1 × S 2-horizon topology. The Rasheed metrics of Section 5.4 provide an example of black holes arising in Kaluza–Klein theories. The Birmingham family of metrics, presented in Section 5.5, forms the most general class known of explicit static vacuum metrics with cosmological constant in all dimensions, with a wide range of horizon topologies.

scholarly journals WEYL INVARIANCE AND SPURIOUS BLACK HOLES IN TWO-DIMENSIONAL DILATON GRAVITY

1994 ◽  
Vol 09 (27) ◽  
pp. 4811-4835 ◽  
Author(s):  
TAKANORI FUJIWARA ◽  
YUJI IGARASHI ◽  
JISUKE KUBO
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hawking Radiation ◽  
Gravity Models ◽  
Conformal Anomaly ◽  
Quantum Level ◽  
Two Dimensional ◽  
Dilaton Gravity ◽  
Matter Coupling ◽  
Weyl Invariance

In two-dimensional dilaton gravity theories, there may exist a global Weyl invariance which makes the black hole spurious. If the global invariance and the local Weyl invariance of the matter coupling are intact at the quantum level, there is no Hawking radiation. We explicitly verify the absence of anomalies in these symmetries for the model proposed by Callan, Giddings, Harvey and Strominger. The crucial observation is that the conformal anomaly can be cohomologically trivial and so not truly anomalous in such dilaton gravity models.

scholarly journals WORMHOLES IN TWO-DIMENSIONAL DILATON GRAVITY

1994 ◽  
Vol 09 (11) ◽  
pp. 959-966 ◽  
Author(s):  
SHIN'ICHI NOJIRI ◽  
ICHIRO ODA
Keyword(s):  
Black Hole ◽  
Black Hole Solution ◽  
Equations Of Motion ◽  
Quantum Corrections ◽  
Two Dimensional ◽  
Dilaton Gravity ◽  
Curvature Singularity ◽  
Wormhole Solution ◽  
Global Event ◽  
Matter Perturbation

It is shown that the general solution of classical equations of motion in two-dimensional dilaton gravity proposed by Callan, Giddings, Harvey and Strominger (CGHS) includes a Lorentzian wormhole solution in addition to a black hole solution. We also show that matter perturbation of the wormhole by a shock wave leads to the formation of a black hole where the curvature singularity is cloaked by the global event horizon. It is also argued that the classical wormhole would be stable against quantum corrections.

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