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 Islands and Page curves in charged dilaton black holes

2022 ◽  
Vol 82 (1) ◽  
Author(s):  
Ming-Hui Yu ◽  
Xian-Hui Ge
Keyword(s):  
Black Holes ◽  
Hawking Radiation ◽  
Entanglement Entropy ◽  
Von Neumann Entropy ◽  
Extremal Case ◽  
Von Neumann ◽  
Asymptotically Flat ◽  
Flat Spacetime ◽  
The Impact ◽  
Dilaton Black Holes

AbstractWe study the Page curve for eternal Garfinkle–Horowitz–Strominger dilaton black holes in four dimensional asymptotically flat spacetime by using the island paradigm. The results demonstrate that without the island, the entanglement entropy of Hawking radiation is proportional to time and becomes divergent at late times. While taking account of the existence of the island outside the event horizon, the entanglement entropy stops growing at late times and eventually reaches a saturation value. This value is twice of the Bekenstein–Hawking entropy and consistent with the finiteness of the von Neumann entropy of eternal black holes. Moreover, we discuss the impact of the stringy coefficient n and charge Q on the Page time and the scrambling time respectively. For the non-extremal case, the influence of the coefficient n on them is small compared to the influence of the charge Q. However, for the extremal case, the Page time and the scrambling time become divergent or near vanishing. This implies the island paradigm needs further investigation.

scholarly journals QUASINORMAL MODES OF CHARGED DILATON BLACK HOLES AND THEIR ENTROPY SPECTRA

2013 ◽  
Vol 28 (27) ◽  
pp. 1350109 ◽  
Author(s):  
I. SAKALLI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quasinormal Modes ◽  
Energy Limit ◽  
Small Perturbations ◽  
Asymptotically Flat ◽  
Dimensionless Constant ◽  
Linear Dilaton ◽  
Linear Dilaton Black Hole ◽  
Dilaton Black Hole

In this study, we employ the scalar perturbations of the charged dilaton black hole (CDBH) found by Chan, Horne and Mann (CHM), and described with an action which emerges in the low-energy limit of the string theory. A CDBH is neither asymptotically flat (AF) nor non-asymptotically flat (NAF) spacetime. Depending on the value of its dilaton parameter a, it has both Schwarzschild and linear dilaton black hole (LDBH) limits. We compute the complex frequencies of the quasinormal modes (QNMs) of the CDBH by considering small perturbations around its horizon. By using the highly damped QNM in the process prescribed by Maggiore, we obtain the quantum entropy and area spectra of these black holes (BHs). Although the QNM frequencies are tuned by a, we show that the quantum spectra do not depend on a, and they are equally spaced. On the other hand, the obtained value of undetermined dimensionless constant ϵ is the double of Bekenstein's result. The possible reason of this discrepancy is also discussed.

scholarly journals THERMODYNAMICS OF NONSPHERICAL BLACK HOLES FROM LIOUVILLE THEORY

2012 ◽  
Vol 27 (20) ◽  
pp. 1250111 ◽  
Author(s):  
FANG-FANG YUAN ◽  
YONG-CHANG HUANG
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Central Charge ◽  
Black Hole Entropy ◽  
Liouville Theory ◽  
Two Dimensional ◽  
Hamiltonian Approach ◽  
Black Rings ◽  
Dimensional Black Hole ◽  
Black Hole Temperature

A Liouville formalism was proposed many years ago to account for the black hole entropy. It was recently updated to connect thermodynamics of general black holes, in particular the Hawking temperature, to two-dimensional Liouville theory. This relies on the dimensional reduction to two-dimensional black hole metric. The relevant dilaton gravity model can be rewritten as a Liouville-like theory. We refine the method and give general formulas for the corresponding scalar and energy–momentum tensors in Liouville theory. This enables us to read off the black hole temperature using a relation which was found about three decades ago. Then the range of application is extended to include nonspherical black holes such as neutral and charged black rings, topological black hole and the case coupled to a scalar field. As for the entropy, following previous authors, we invoke the Lagrangian approach to central charge by Cadoni and then use the Cardy formula. The general relevant parameters are also given. This approach is more advantageous than the usual Hamiltonian approach which was used by the old Liouville formalism for black hole entropy.

CAN SMALL TWO-DIMENSIONAL BLACK HOLES EXIST?

1987 ◽  
Vol 02 (08) ◽  
pp. 555-560 ◽  
Author(s):  
O. J. KWON ◽  
B. H. CHO ◽  
Y. S. MYUNG
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Two Dimensional ◽  
Classical Stability ◽  
Dimensional Black Hole ◽  
Pure Gravity

We discuss the classical stability of a two-dimensional black hole which arises from the Jackiw model and pure gravity with a curvature squared term. For both these two models, we find that there exists the exponentially growing mode with time. Therefore, it seems that a two-dimensional black hole does not truly exist.

scholarly journals Islands in multiverse models

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Sergio E. Aguilar-Gutierrez ◽  
Aidan Chatwin-Davies ◽  
Thomas Hertog ◽  
Natalia Pinzani-Fokeeva ◽  
Brandon Robinson
Keyword(s):  
Saddle Point ◽  
Quantum Cosmology ◽  
Von Neumann Entropy ◽  
Coarse Grain ◽  
Two Dimensional ◽  
Dilaton Gravity ◽  
False Vacuum ◽  
Von Neumann ◽  
Eternal Inflation ◽  
Linear Dilaton

Abstract We consider multiverse models in two-dimensional linear dilaton-gravity theories as toy models of false vacuum eternal inflation. Coupling conformal matter we calculate the Von Neumann entropy of subregions. When these are sufficiently large we find that an island develops covering most of the rest of the multiverse, leading to a Page-like transition. This resonates with a description of multiverse models in semiclassical quantum cosmology, where a measure for local predictions is given by saddle point geometries which coarse-grain over any structure associated with eternal inflation beyond one’s patch.

scholarly journals QUANTIZATION OF HIGHER-DIMENSIONAL LINEAR DILATON BLACK HOLE AREA/ENTROPY FROM QUASINORMAL MODES

2011 ◽  
Vol 26 (13) ◽  
pp. 2263-2269 ◽  
Author(s):  
I. SAKALLI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quasinormal Modes ◽  
Time Dimension ◽  
Hole Area ◽  
Higher Dimensional ◽  
Linear Dilaton ◽  
Linear Dilaton Black Hole ◽  
Dilaton Black Hole ◽  
Dilaton Black Holes

The quantum spectra of area and entropy of higher-dimensional linear dilaton black holes in various theories via the quasinormal modes method are studied. It is shown that quasinormal modes of these black holes can reveal themselves when a specific condition holds. Finally, we obtain that a higher-dimensional linear dilaton black hole has equidistant area and entropy spectra, and both of them are independent on the space–time dimension.

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 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 Islands and Page curves of Reissner-Nordström black holes

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Xuanhua Wang ◽  
Ran Li ◽  
Jin Wang
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hawking Radiation ◽  
Entanglement Entropy ◽  
Additional Term ◽  
Current Case ◽  
Information Paradox ◽  
Extremal Surface ◽  
Four Dimensions ◽  
Black Hole Information

Abstract We apply the recently proposed quantum extremal surface construction to calculate the Page curve of the eternal Reissner-Nordström black holes in four dimensions ignoring the backreaction and the greybody factor. Without the island, the entropy of Hawking radiation grows linearly with time, which results in the information paradox for the eternal black holes. By extremizing the generalized entropy that allows the contributions from the island, we find that the island extends to the outside the horizon of the Reissner-Nordström black hole. When taking the effect of the islands into account, it is shown that the entanglement entropy of Hawking radiation at late times for a given region far from the black hole horizon reproduces the Bekenstein-Hawking entropy of the Reissner-Nordström black hole with an additional term representing the effect of the matter fields. The result is consistent with the finiteness of the entanglement entropy for the radiation from an eternal black hole. This facilitates to address the black hole information paradox issue in the current case under the above-mentioned approximations.

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