Gielen, S. orcid.org/0000-0002-8653-5430 and Menéndez-Pidal, L. (2022) Unitarity and quantum resolution of gravitational singularities. International Journal of Modern Physics D, 31 (14). 2241005. ISSN 0218-2718
Abstract
Here, we explore the consequences of requiring that quantum theories of gravity be unitary, mostly focusing on simple cosmological models to illustrate the main points. We show that unitarity for a clock that encounters a classical singularity at finite time implies quantum singularity resolution, but for a clock that encounters future infinity at finite time leads to a quantum recollapse. We then find that our starting point — assuming the general covariance of general relativity — is actually incompatible with general quantum unitarity: singularity resolution in quantum gravity can always be engineered by choosing the right clock, or avoided by using a different one.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2022 World Scientific Publishing Co Pte Ltd. This is an author-produced version of a paper subsequently published in International Journal of Modern Physics D. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Unitarity; singularity resolution; quantum cosmology |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematics and Statistics (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 10 Nov 2022 16:51 |
Last Modified: | 25 Sep 2024 13:12 |
Status: | Published |
Publisher: | World Scientific Pub Co Pte Ltd |
Refereed: | Yes |
Identification Number: | 10.1142/s021827182241005x |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:193152 |