Unitarity and quantum resolution of gravitational singularities
| Autor: | Steffen Gielen, Lucía Menéndez-Pidal |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
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| Popis: | 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. 9 pages, 5 figures; Fifth Award in the Gravity Research Foundation 2022 Awards for Essays on Gravitation. v2: minor typographical changes. To be published in Int.J.Mod.Phys.D |
| Databáze: | OpenAIRE |
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