Emergent diffeomorphism invariance in toy models

Nikolić, Hrvoje (2023) Emergent diffeomorphism invariance in toy models. Fortschritte der Physik - Progress of Physics, 71 (8-9). ISSN 1521-3978

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Abstract

Conceptual difficulties in semiclassical and quantum gravity arise from diffeomorphism invariance of classical general relativity. With a motivation to shed some light on these difficulties, we study a class of toy models for which one-dimensional diffeomorphism invariance, namely time-reparametrization invariance, emerges at the classical level from energy conservation. An attempt to quantize the models while taking the invariance seriously leads to toy versions of the problem of time in quantum gravity, of the cosmological constant problem, and of the black hole firewall problem. Nevertheless, all these problems are easily resolved by taking into account that the invariance emerges only at the classical level, while the fundamental theory that needs to be quantized is not diffeomorphism invariant.

Item Type:	Article
Additional Information:	Imported from arXiv
Uncontrolled Keywords:	emergent gravity; diffeomorphism invariance; time in quantum gravity; cosmological constant; black hole firewall
Subjects:	NATURAL SCIENCES > Physics > Physics of Elementary Particles and Fields
Divisions:	Theoretical Physics Division
Depositing User:	Tajron Jurić
Date Deposited:	07 Jan 2025 15:13
URI:	http://fulir.irb.hr/id/eprint/9365
DOI:	10.1002/prop.202300026

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