scholarly journals Circuit Complexity from Cosmological Islands

2021 ◽  
Author(s):  
Sayantan Choudhury ◽  
Satyaki Chowdhury ◽  
Sudhakar Panda ◽  
Abinash Swain ◽  
Nitin Gupta ◽  
...  
Keyword(s):  
Black Hole ◽  
Parameter Space ◽  
Entanglement Entropy ◽  
Cosmological Solution ◽  
Circuit Complexity ◽  
Space Time ◽  
Squeezed State ◽  
Positive Cosmological Constant ◽  
Black Hole Information ◽  
Made In

Recently in various theoretical works, path-breaking progress has been made in recovering the well-known Page Curve of an evaporating black hole with Quantum Extremal Islands, proposed to solve the long-standing black hole information loss problem related to the unitarity issue. Motivated by this concept, in this paper, we study cosmological circuit complexity in the presence (or absence) of Quantum Extremal Islands in negative (or positive) Cosmological Constant with radiation in the background of Friedmann-Lemaî tre-Robertson-Walker (FLRW) space-time. Without using any explicit details of any gravity model, we study the behaviour of the circuit complexity function with respect to the dynamical cosmological solution for the scale factors for the above mentioned two situations in FLRW space-time using squeezed state formalism. By studying the cosmological circuit complexity, Out-of-Time Ordered Correlators, and entanglement entropy of the modes of the squeezed state, in different parameter space, we conclude the non-universality of these measures. Their remarkably different features in the different parameter space suggests their dependence on the parameters of the model under consideration.

scholarly journals Circuit Complexity from Cosmological Islands

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1301
Author(s):  
Sayantan Choudhury ◽  
Satyaki Chowdhury ◽  
Nitin Gupta ◽  
Anurag Mishara ◽  
Sachin Panneer Selvam ◽  
...  
Keyword(s):  
Black Hole ◽  
Parameter Space ◽  
Entanglement Entropy ◽  
Cosmological Solution ◽  
Circuit Complexity ◽  
Space Time ◽  
De Sitter ◽  
Squeezed State ◽  
Black Hole Information ◽  
Made In

Recently, in various theoretical works, path-breaking progress has been made in recovering the well-known page curve of an evaporating black hole with quantum extremal islands, proposed to solve the long-standing black hole information loss problem related to the unitarity issue. Motivated by this concept, in this paper, we study cosmological circuit complexity in the presence (or absence) of quantum extremal islands in negative (or positive) cosmological constant with radiation in the background of Friedmann-Lemai^tre-Robertson-Walker (FLRW) space-time, i.e., the presence and absence of islands in anti de Sitter and the de Sitter space-time having SO(2, 3) and SO(1, 4) isometries, respectively. Without using any explicit details of any gravity model, we study the behavior of the circuit complexity function with respect to the dynamical cosmological solution for the scale factors for the above mentioned two situations in FLRW space-time using squeezed state formalism. By studying the cosmological circuit complexity, out-of-time ordered correlators, and entanglement entropy of the modes of the squeezed state, in different parameter space, we conclude the non-universality of these measures. Their remarkably different features in the different parameter space suggests their dependence on the parameters of the model under consideration.

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.

scholarly journals Local quenches, bulk entanglement entropy and a unitary Page curve

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Cesar A. Agón ◽  
Sagar F. Lokhande ◽  
Juan F. Pedraza
Keyword(s):  
Black Hole ◽  
Entanglement Entropy ◽  
Quantum Corrections ◽  
Massive Scalar Field ◽  
Black Hole Evaporation ◽  
Primary Operator ◽  
Black Hole Information ◽  
Information Problem ◽  
Matter Fields ◽  
Entropy Corrections

Abstract Quantum corrections to the entanglement entropy of matter fields interacting with dynamical gravity have proven to be very important in the study of the black hole information problem. We consider a one-particle excited state of a massive scalar field infalling in a pure AdS3 geometry and compute these corrections for bulk subregions anchored on the AdS boundary. In the dual CFT2, the state is given by the insertion of a local primary operator and its evolution thereafter. We calculate the area and bulk entanglement entropy corrections at order $$ \mathcal{O}\left({N}^0\right), $$ O N 0 , both in AdS and its CFT dual. The two calculations match, thus providing a non-trivial check of the FLM formula in a dynamical setting. Further, we observe that the bulk entanglement entropy follows a Page curve. We explain the precise sense in which our setup can be interpreted as a simple model of black hole evaporation and comment on the implications for the information problem.

scholarly journals Island in charged black holes

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Yi Ling ◽  
Yuxuan Liu ◽  
Zhuo-Yu Xian
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Degrees Of Freedom ◽  
Entanglement Entropy ◽  
Information Paradox ◽  
Extremal Surface ◽  
Charged Black Holes ◽  
Dimensional Spacetime ◽  
Black Hole Information ◽  
Extremal Black Holes

Abstract We study the information paradox for the eternal black hole with charges on a doubly-holographic model in general dimensions, where the charged black hole on a Planck brane is coupled to the baths on the conformal boundaries. In the case of weak tension, the brane can be treated as a probe such that its backreaction to the bulk is negligible. We analytically calculate the entanglement entropy of the radiation and obtain the Page curve with the presence of an island on the brane. For the near-extremal black holes, the growth rate is linear in the temperature. Taking both Dvali-Gabadadze-Porrati term and nonzero tension into account, we obtain the numerical solution with backreaction in four-dimensional spacetime and find the quantum extremal surface at t = 0. To guarantee that a Page curve can be obtained in general cases, we propose two strategies to impose enough degrees of freedom on the brane such that the black hole information paradox can be properly described by the doubly-holographic setup.

scholarly journals Islands and Page curves in 4d from Type IIB

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Christoph F. Uhlemann
Keyword(s):  
Black Hole ◽  
String Theory ◽  
Entanglement Entropy ◽  
Critical Parameters ◽  
Brane Worlds ◽  
Black Hole Radiation ◽  
Entropy Of Black Hole ◽  
Dimensional Gravity ◽  
Black Hole Information ◽  
Type Iib String Theory

Abstract Variants of the black hole information paradox are studied in Type IIB string theory setups that realize four-dimensional gravity coupled to a bath. The setups are string theory versions of doubly-holographic Karch/Randall brane worlds, with black holes coupled to non-gravitating and gravitating baths. The 10d versions are based on fully backreacted solutions for configurations of D3, D5 and NS5 branes, and admit dual descriptions as $$ \mathcal{N} $$ N = 4 SYM on a half space and 3d $$ {T}_{\rho}^{\sigma } $$ T ρ σ [SU(N)] SCFTs. Island contributions to the entanglement entropy of black hole radiation systems are identified through Ryu/Takayanagi surfaces and lead to Page curves. Analogs of the critical angles found in the Karch/Randall models are identified in 10d, as critical parameters in the brane configurations and dual field theories.

scholarly journals Fermion Fields in BTZ Black Hole Space-Time and Entanglement Entropy

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Dharm Veer Singh ◽  
Sanjay Siwach
Keyword(s):  
Black Hole ◽  
Entanglement Entropy ◽  
Black Hole Entropy ◽  
Mass Term ◽  
Space Time ◽  
Btz Black Hole ◽  
Logarithmic Divergence ◽  
Fermion Fields ◽  
Leading Term ◽  
Area Law

We study the entanglement entropy of fermion fields in BTZ black hole space-time and calculate prefactor of the leading and subleading terms and logarithmic divergence term of the entropy using the discretized model. The leading term is the standard Bekenstein-Hawking area law and subleading term corresponds to first quantum corrections in black hole entropy. We also investigate the corrections to entanglement entropy for massive fermion fields in BTZ space-time. The mass term does not affect the area law.

scholarly journals On the Mathematical Analysis of Black-Hole Information Loss Paradox

2013 ◽  
Vol 18 ◽  
pp. 8-12
Author(s):  
V. Vishal ◽  
B. Siddharth ◽  
C. Venkatachalam
Keyword(s):  
Black Hole ◽  
Space Time ◽  
Brane World ◽  
Information Storage ◽  
Information Loss Paradox ◽  
The Past ◽  
Dimensional Gravity ◽  
Gravitational Singularity ◽  
Black Hole Information ◽  
Inverse Functions

A Black-hole is an astronomical entity which possesses infinite density at its gravitational singularity or singular point. The capacity of a black-hole to completely rip-off an entire solar system without leaving any evidence is to be noted. A debate has been going on over the past few decades regarding the information storage in black-holes. The discovery of Hawking radiation, which predicts complete evaporation of mass violates unitarity ie. Conservation of probability and energy fails. Recent discoveries suggest that regular remnant of black-hole survives evaporation , as a result information of the object devoured can be contained. These remnants are grouped into embedded sub-manifolds. These manifolds are the result of a five-dimensional constant curvature bulk in space-time. Five-dimensional gravity can be recovered from brane-world resulting from equations of bulk geometry. Gravity can be explained by space-time theory and also quantum theory in the form of Gravitons. On observing the manifold, the gravitons show deformations in dimensions, rather than being constant. The perturbations in geometry can be related to embedding functions which should remain differentiable and regular. Regularity is related to the inverse functions theorem. Manifold observations followed by a mathematical approach can possibly retain information about objects devoured by the black-hole.

scholarly journals SPACE TIME FOAM

2002 ◽  
Vol 17 (06n07) ◽  
pp. 829-832 ◽  
Author(s):  
REMO GARATTINI
Keyword(s):  
Black Hole ◽  
Cosmological Constant ◽  
Ground State ◽  
Casimir Energy ◽  
Space Time ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Positive Cosmological Constant ◽  
Hole Transition

In the context of a model of space-time foam, made by N wormholes we discuss the possibility of having a foam formed by different configurations. An equivalence between Schwarzschild and Schwarzschild-Anti-de Sitter wormholes in terms of Casimir energy is shown. An argument to discriminate which configuration could represent a foamy vacuum coming from Schwarzschild black hole transition frequencies is used. The case of a positive cosmological constant is also discussed. Finally, a discussion involving charged wormholes leads to the conclusion that they cannot be used to represent a ground state of the foamy type.

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.

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