scholarly journals The price of curiosity: information recovery in de Sitter space

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Lars Aalsma ◽  
Watse Sybesma
Keyword(s):  
Black Hole ◽  
Thermal Equilibrium ◽  
De Sitter Space ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Information Recovery ◽  
Fine Grained ◽  
Black Hole Radiation ◽  
Entropy Of Black Hole

Abstract Recent works have revealed that quantum extremal islands can contribute to the fine-grained entropy of black hole radiation reproducing the unitary Page curve. In this paper, we use these results to assess if an observer in de Sitter space can decode information hidden behind their cosmological horizon. By computing the fine-grained entropy of the Gibbons-Hawking radiation in a region where gravity is weak we find that this is possible, but the observer’s curiosity comes at a price. At the same time the island appears, which happens much earlier than the Page time, a singularity forms which the observer will eventually hit. We arrive at this conclusion by studying de Sitter space in Jackiw-Teitelboim gravity. We emphasize the role of the observer collecting radiation, breaking the thermal equilibrium studied so far in the literature. By analytically solving for the backreacted geometry we show how an island appears in this out-of-equilibrium state.

scholarly journals THE CARDY–VERLINDE FORMULA AND ENTROPY OF TOPOLOGICAL REISSNER–NORDSTRÖM BLACK HOLES IN DE SITTER SPACES

2002 ◽  
Vol 17 (32) ◽  
pp. 2089-2094 ◽  
Author(s):  
M. R. SETARE
Keyword(s):  
Field Theory ◽  
Black Holes ◽  
Black Hole ◽  
Conformal Field Theory ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Conformal Field ◽  
Entropy Formula ◽  
Verlinde Formula ◽  
Entropy Of Black Hole

In this paper we discuss the question of whether the entropy of cosmological horizon in topological Reissner–Nordström–de Sitter spaces can be described by the Cardy–Verlinde formula, which is supposed to be an entropy formula of conformal field theory in any dimension. Furthermore, we find that the entropy of black hole horizon can also be rewritten in terms of the Cardy–Verlinde formula for these black holes in de Sitter spaces, if we use the definition due to Abbott and Deser for conserved charges in asymptotically de Sitter spaces. Our result is in favour of the dS/CFT correspondence.

scholarly journals On the Schwarzschild-Anti-de Sitter black hole with an f(R) global monopole

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
H. S. Vieira
Keyword(s):  
Black Hole ◽  
Gordon Equation ◽  
Global Monopole ◽  
De Sitter ◽  
Scalar Particles ◽  
Black Hole Radiation ◽  
Effective Cosmological Constant ◽  
Klein Gordon ◽  
Physical Phenomena

AbstractIn this work, we follow the recently revisited f(R) theory of gravity for studying the interaction between quantum scalar particles and the gravitational field of a generalized black hole with an f(R) global monopole. This background has a term playing the role of an effective cosmological constant, which permits us to call it as Schwarzschild-Anti-de Sitter (SAdS) black hole with an f(R) global monopole. We examine the separability of the Klein–Gordon equation with a non-minimal coupling and then we discuss both the massless and massive cases for a conformal coupling. We investigate some physical phenomena related to the asymptotic behavior of the radial function, namely, the black hole radiation, the quasibound states, and the wave eigenfunctions.

scholarly journals Shocks and information exchange in de Sitter space

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
L. Aalsma ◽  
A. Cole ◽  
E. Morvan ◽  
J. P. van der Schaar ◽  
G. Shiu
Keyword(s):  
Black Hole ◽  
Information Exchange ◽  
Information Transfer ◽  
Recent Progress ◽  
Vacuum State ◽  
De Sitter Space ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Black Hole Information ◽  
Selection Of

Abstract We discuss some implications of recent progress in understanding the black hole information paradox for complementarity in de Sitter space. Extending recent work by two of the authors, we describe a bulk procedure that allows information expelled through the cosmological horizon to be received by an antipodal observer. Generically, this information transfer takes a scrambling time t = H−1 log(SdS). We emphasize that this procedure relies crucially on selection of the Bunch-Davies vacuum state, interpreted as the thermofield double state that maximally entangles two antipodal static patches. The procedure also requires the presence of an (entangled) energy reservoir, created by the collection of Hawking modes from the cosmological horizon. We show how this procedure avoids a cloning paradox and comment on its implications.

scholarly journals Reparameterization dependence is useful for holographic complexity

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Ayoub Mounim ◽  
Wolfgang Mück
Keyword(s):  
Black Hole ◽  
Critical Time ◽  
De Sitter Space ◽  
Time Interval ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Static Vacuum ◽  
Reparameterization Invariance ◽  
Negative Time

Abstract Holographic complexity in the “complexity equals action” approach is reconsidered relaxing the requirement of reparameterization invariance of the action with the prescription that the action vanish in any static, vacuum causal diamond. This implies that vacuum anti-de Sitter space plays the role of the reference state. Moreover, the complexity of an anti-de Sitter-Schwarzschild black hole becomes intrinsically finite and saturates Lloyd’s bound after a critical time. It is also argued that several artifacts, such as the unphysical negative-time interval, can be removed by truly considering the bulk dual of the thermofield double state.

scholarly journals Islands in de Sitter space

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Vijay Balasubramanian ◽  
Arjun Kar ◽  
Tomonori Ugajin
Keyword(s):  
Black Hole ◽  
Entanglement Entropy ◽  
De Sitter Space ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Replica Trick ◽  
Compact Geometry ◽  
Entropy Growth ◽  
Spatial Section ◽  
Conventional Field

Abstract We consider black holes in 2d de Sitter JT gravity coupled to a CFT, and entangled with matter in a disjoint non-gravitating universe. Tracing out the entangling matter leaves the CFT in a density matrix whose stress tensor backreacts on the de Sitter geometry, lengthening the wormhole behind the black hole horizon. Naively, the entropy of the entangling matter increases without bound as the strength of the entanglement increases, but the monogamy property predicts that this growth must level off. We compute the entropy via the replica trick, including wormholes between the replica copies of the de Sitter geometry, and find a competition between conventional field theory entanglement entropy and the surface area of extremal “islands” in the de Sitter geometry. The black hole and cosmological horizons both play a role in generating such islands in the backreacted geometry, and have the effect of stabilizing the entropy growth as required by monogamy. We first show this in a scenario in which the de Sitter spatial section has been decompactified to an interval. Then we consider the compact geometry, and argue for a novel interpretation of the island formula in the context of closed universes that recovers the Page curve. Finally, we comment on the application of our construction to the cosmological horizon in empty de Sitter space.

Noncommutative scalar field in de Sitter space–time and pair creation process

2021 ◽  
Vol 36 (02) ◽  
pp. 2150011
Author(s):  
Nabil Mehdaoui ◽  
Lamine Khodja ◽  
Salah Haouat
Keyword(s):  
Scalar Field ◽  
Chemical Potential ◽  
De Sitter Space ◽  
Space Time ◽  
Pair Creation ◽  
De Sitter ◽  
Creation Process ◽  
Scalar Particles ◽  
Constant Electromagnetic Field

In this work, we address the process of pair creation of scalar particles in [Formula: see text] de Sitter space–time in presence of a constant electromagnetic field by applying the noncommutativity on the scalar field up to first-order in [Formula: see text]. We calculate the density of particles created in the vacuum by the mean of the Bogoliubov transformations. In contrast to a previous result, we show that noncommutativity contributes to the pair creation process. We find that the noncommutativity plays the same role of chemical potential and gives an important interest for studies at high energies.

scholarly journals Towards causal patch physics in dS/CFT

2018 ◽  
Vol 168 ◽  
pp. 01007 ◽  
Author(s):  
Yasha Neiman
Keyword(s):  
Field Theory ◽  
Higher Spin Gravity ◽  
De Sitter Space ◽  
Vector Model ◽  
Status Report ◽  
Quantum Field ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Higher Spin ◽  
Holographic Description

This contribution is a status report on a research program aimed at obtaining quantum-gravitational physics inside a cosmological horizon through dS/CFT, i.e. through a holographic description at past/future infinity of de Sitter space. The program aims to bring together two main elements. The first is the observation by Anninos, Hartman and Strominger that Vasiliev’s higher-spin gravity provides a working model for dS/CFT in 3+1 dimensions. The second is the proposal by Parikh, Savonije and Verlinde that dS/CFT may prove more tractable if one works in so-called “elliptic” de Sitter space – a folded-in-half version of global de Sitter where antipodal points have been identified. We review some relevant progress concerning quantum field theory on elliptic de Sitter space, higher-spin gravity and its holographic duality with a free vector model. We present our reasons for optimism that the approach outlined here will lead to a full holographic description of quantum (higher-spin) gravity in the causal patch of a de Sitter observer.

ENTROPY OF SCHWARZSCHILD–de SITTER BLACK HOLE IN NON-THERMAL-EQUILIBRIUM

2001 ◽  
Vol 16 (11) ◽  
pp. 719-723 ◽  
Author(s):  
REN ZHAO ◽  
JUNFANG ZHANG ◽  
LICHUN ZHANG
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Thermal Equilibrium ◽  
Gordon Equation ◽  
Brick Wall ◽  
De Sitter ◽  
Logarithmic Term ◽  
Klein Gordon ◽  
Klein Gordon Equation ◽  
Wall Method

Starting from the Klein–Gordon equation, we calculate the entropy of Schwarzschild–de Sitter black hole in non-thermal-equilibrium by using the improved brick-wall method-membrane model. When taking the proper cutoff in the obtained result, we obtain that both black hole's entropy and cosmic entropy are proportional to the areas of event horizon. We avoid the logarithmic term and stripped term in the original brick-wall method. It offers a new way of studying the entropy of the black hole in non-thermal-equilibrium.

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