Spacetime topology change and 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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Global symmetry, Euclidean gravity, and the black hole information problem

Journal of High Energy Physics ◽

10.1007/jhep04(2021)175 ◽

2021 ◽

Vol 2021 (4) ◽

Author(s):

Daniel Harlow ◽

Edgar Shaghoulian

Keyword(s):

Black Hole ◽

Quantum Gravity ◽

Global Symmetries ◽

Close Connection ◽

Usual Sense ◽

Global Symmetry ◽

Recent Argument ◽

Black Hole Information ◽

Information Problem ◽

Low Dimensional

Abstract In this paper we argue for a close connection between the non-existence of global symmetries in quantum gravity and a unitary resolution of the black hole information problem. In particular we show how the essential ingredients of recent calculations of the Page curve of an evaporating black hole can be used to generalize a recent argument against global symmetries beyond the AdS/CFT correspondence to more realistic theories of quantum gravity. We also give several low-dimensional examples of quantum gravity theories which do not have a unitary resolution of the black hole information problem in the usual sense, and which therefore can and do have global symmetries. Motivated by this discussion, we conjecture that in a certain sense Euclidean quantum gravity is equivalent to holography.

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A PROPOSAL TO RESOLVE THE BLACK HOLE INFORMATION PARADOX

International Journal of Modern Physics D ◽

10.1142/s0218271802002852 ◽

2002 ◽

Vol 11 (10) ◽

pp. 1537-1540 ◽

Cited By ~ 15

Author(s):

SAMIR D. MATHUR

Keyword(s):

Black Holes ◽

Black Hole ◽

String Theory ◽

Quantum Gravity ◽

Bound State ◽

Nonlocal Effects ◽

Information Paradox ◽

Microscopic Scale ◽

Gravity Effects ◽

Black Hole Information

The entropy and information puzzles arising from black holes cannot be resolved if quantum gravity effects remain confined to a microscopic scale. We use concrete computations in nonperturbative string theory to argue for three kinds of nonlocal effects that operate over macroscopic distances. These effects arise when we make a bound state of a large number of branes, and occur at the correct scale to resolve the paradoxes associated with black holes.

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Matrix models for the black hole information paradox

Journal of High Energy Physics ◽

10.1007/jhep02(2010)073 ◽

2010 ◽

Vol 2010 (2) ◽

Cited By ~ 19

Author(s):

Norihiro Iizuka ◽

Takuya Okuda ◽

Joseph Polchinski

Keyword(s):

Black Hole ◽

Matrix Models ◽

Information Paradox ◽

Black Hole Information

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A COMMENT ON THE BLACK HOLE INFORMATION PARADOX

International Journal of Modern Physics A ◽

10.1142/s0217751x01008710 ◽

2001 ◽

Vol 16 (supp01c) ◽

pp. 1001-1004

Author(s):

SAMIR D. MATHUR

Keyword(s):

Black Holes ◽

Black Hole ◽

String Theory ◽

Information Paradox ◽

Loss Of Information ◽

Black Hole Information ◽

Classical Gravity ◽

New Criterion

Results from string theory strongly suggest that formation and evaporation of black holes is a unitary process. Thus we must find a flaw in the semiclassical reasoning that implies a loss of information. We propose a new criterion that limits the domain of classical gravity: the hypersurfaces of a foliation cannot be stretched too much.

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Wormhole calculus, replicas, and entropies

Journal of High Energy Physics ◽

10.1007/jhep09(2020)194 ◽

2020 ◽

Vol 2020 (9) ◽

Cited By ~ 2

Author(s):

Steven B. Giddings ◽

Gustavo J. Turiaci

Keyword(s):

Black Hole ◽

Probability Distributions ◽

Information Loss ◽

Coupling Constants ◽

Quantum Mechanical ◽

Standard Description ◽

Standard Quantum ◽

Black Hole Information ◽

Baby Universes ◽

Baby Universe

Abstract We investigate contributions of spacetime wormholes, describing baby universe emission and absorption, to calculations of entropies and correlation functions, for example those based on the replica method. We find that the rules of the “wormhole calculus”, developed in the 1980s, together with standard quantum mechanical prescriptions for computing entropies and correlators, imply definite rules for limited patterns of connection between replica factors in simple calculations. These results stand in contrast with assumptions that all topologies connecting replicas should be summed over, and call into question the explanation for the latter. In a “free” approximation baby universes introduce probability distributions for coupling constants, and we review and extend arguments that successive experiments in a “parent” universe increasingly precisely fix such couplings, resulting in ultimately pure evolution. Once this has happened, the nontrivial question remains of how topology-changing effects can modify the standard description of black hole information loss.

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