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Title: Branches of the black hole wave function need not contain firewalls

Abstract

We discuss the branching structure of the quantum-gravitational wave function that describes the evaporation of a black hole. A global wave function which initially describes a classical Schwarzschild geometry is continually decohered into distinct semiclassical branches by the emission of Hawking radiation. The laws of quantum mechanics dictate that the wave function evolves unitarily, but this unitary evolution is only manifest when considering the global description of the wave function; it is not implemented by time evolution on a single semiclassical branch. Conversely, geometric notions like the position or smoothness of a horizon only make sense on the level of individual branches. We consider the implications of this picture for probes of black holes by classical observers in definite geometries, like those involved in the Almheiri-Marolf-Polchinski-Sully construction. We argue that individual branches can describe semiclassical geometries free of firewalls, even as the global wave function evolves unitarily. We show that the pointer states of infalling detectors that are robust under Hamiltonian evolution are distinct from, and incompatible with, those of exterior detectors stationary with respect to the black hole horizon, in the sense that the pointer bases are related to each other via nontrivial transformations that mix the system, apparatus,more » and environment. This result describes a Hilbert-space version of black hole complementarity.« less

Authors:
 [1];  [2];  [2];  [3];  [1]
  1. Univ. of California, Berkeley, CA (United States). Berkeley Center for Theoretical Physics
  2. California Inst. of Technology (CalTech), Pasadena, CA (United States). Walter Burke Inst. for Theoretical Physics
  3. Univ. of British Columbia, Vancouver, BC (Canada). Dept. of Physics and Astronomy
Publication Date:
Research Org.:
California Inst. of Technology (CalTech), Pasadena, CA (United States). Chemical Engineering
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1455097
Alternate Identifier(s):
OSTI ID: 1501538
Grant/Contract Number:  
SC0011632
Resource Type:
Published Article
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 97; Journal Issue: 12; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS

Citation Formats

Bao, Ning, Carroll, Sean M., Chatwin-Davies, Aidan, Pollack, Jason, and Remmen, Grant N. Branches of the black hole wave function need not contain firewalls. United States: N. p., 2018. Web. doi:10.1103/physrevd.97.126014.
Bao, Ning, Carroll, Sean M., Chatwin-Davies, Aidan, Pollack, Jason, & Remmen, Grant N. Branches of the black hole wave function need not contain firewalls. United States. doi:10.1103/physrevd.97.126014.
Bao, Ning, Carroll, Sean M., Chatwin-Davies, Aidan, Pollack, Jason, and Remmen, Grant N. Wed . "Branches of the black hole wave function need not contain firewalls". United States. doi:10.1103/physrevd.97.126014.
@article{osti_1455097,
title = {Branches of the black hole wave function need not contain firewalls},
author = {Bao, Ning and Carroll, Sean M. and Chatwin-Davies, Aidan and Pollack, Jason and Remmen, Grant N.},
abstractNote = {We discuss the branching structure of the quantum-gravitational wave function that describes the evaporation of a black hole. A global wave function which initially describes a classical Schwarzschild geometry is continually decohered into distinct semiclassical branches by the emission of Hawking radiation. The laws of quantum mechanics dictate that the wave function evolves unitarily, but this unitary evolution is only manifest when considering the global description of the wave function; it is not implemented by time evolution on a single semiclassical branch. Conversely, geometric notions like the position or smoothness of a horizon only make sense on the level of individual branches. We consider the implications of this picture for probes of black holes by classical observers in definite geometries, like those involved in the Almheiri-Marolf-Polchinski-Sully construction. We argue that individual branches can describe semiclassical geometries free of firewalls, even as the global wave function evolves unitarily. We show that the pointer states of infalling detectors that are robust under Hamiltonian evolution are distinct from, and incompatible with, those of exterior detectors stationary with respect to the black hole horizon, in the sense that the pointer bases are related to each other via nontrivial transformations that mix the system, apparatus, and environment. This result describes a Hilbert-space version of black hole complementarity.},
doi = {10.1103/physrevd.97.126014},
journal = {Physical Review D},
number = 12,
volume = 97,
place = {United States},
year = {2018},
month = {6}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1103/physrevd.97.126014

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