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Cited by 42Black Holes and Theoretical PhysicsNoncommutative and Quantum Gravity TheoriesCosmology and Gravitation Theories

Black holes, quantum theory and cosmology

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Penrose, Roger·2009·Journal of Physics Conference Series
DOI 10.1088/1742-6596/174/1/012001
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Abstract

Some reasons are given for believing that the rules of quantum (field) theory must be changed when general relativity becomes seriously involved. If full quantum mechanical respect is paid to the principle of equivalence, we find that a superposition of gravitational fields leads to an illegal superposition of different vacua, giving support to a proposal for spontaneous quantum state reduction made earlier by Diósi, and then independently by the author. A different line of attack involves the over-riding role of black holes in the total entropy content of the universe, and in the operation of the 2nd Law of thermodynamics. The author's proposal of conformal cyclic cosmology is reviewed in order to highlight a seeming paradox, according to which the entropy of the universe of the remote future seems to return to the small kind of value that it had at the big bang. The paradox is resolved when we take into account the information loss that, from this perspective, necessarily occurs in Hawking's black-hole evaporation, with the accompanying loss of unitarity.

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Crossref · 10.1088/1742-6596/174/1/012001

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39 of 39 references verified0 citation errors · 0 not checkable

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  • In DP, the reduction R of the quantum state is an actual physical process not part of conventional unitary formalism, resulting from melding general relativity with quantum formalism.

    “In the DP version of OR, the reduction R of the quantum state does not arise as some kind of convenience or effective consequence of environmental decoherence, etc., as the conventional U formalism would seem to demand, but is instead taken to be one of the consequences of melding together the principles of Einstein's general relativity with those of the conventional unitary quantum formalism U,”

    From Consciousness in the universe (2014) · cites this paper as [95]

  • DP is a proposal for extending quantum mechanics that takes the bridge between quantum and classical physics as a quantum-gravitational phenomenon.

    “Diósi-Penrose objective reduction (DP) is a particular proposal for an extension of current quantum mechanics, taking the bridge between quantum-and classical-level physics as a 'quantum-gravitational' phenomenon.”

    From Consciousness in the universe (2014) · cites this paper as [95]

  • The Diósi-Penrose (DP) proposal gives an objective physical threshold, providing a plausible lifetime for quantum-superposed states.

    “The DP proposal gives an objective physical threshold, providing a plausible lifetime for quantum-superposed states.”

    From Consciousness in the universe (2014) · cites this paper as [95]

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Authors
Penrose, R.
Affiliations
University of Oxford (GB)
Corresponding author
Penrose, Roger
Venue
Journal of Physics Conference Series
Publisher
IOP Publishing
Published
2009-06-01
Volume
174
Pages
012001
ISSN
  • 1742-6588 (ISSN-L)
  • 1742-6596
DOI
10.1088/1742-6596/174/1/012001
OpenAlex
W2023210939
Cited by
42
References
39
Citations by year
2026: 1 · 2025: 2 · 2024: 3 · 2023: 1 · 2021: 2 · 2020: 2 · 2019: 4 · 2018: 1 · 2017: 2 · 2016: 4 · 2015: 1 · 2014: 5 · 2013: 6 · 2012: 4
FWCI
12.35
Type
conference paper
Language
en
Open access
Locations
Journal of Physics Conference Series (publishedVersion)
Topics
  • Physical Sciences › Physics and Astronomy › Nuclear and High Energy Physics › Black Holes and Theoretical Physics
  • Physical Sciences › Physics and Astronomy › Statistical and Nonlinear Physics › Noncommutative and Quantum Gravity Theories
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Cosmology and Gravitation Theories
Keywords
black holes, quantum gravity, equivalence principle, quantum state reduction, black hole entropy, second law of thermodynamics, conformal cyclic cosmology, information loss, Hawking radiation, unitarity, cosmological entropy

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