Indications against dynamical CPT symmetry restoration in quantum gravity
πΆβ’πβ’π symmetry is at the heart of the standard model of particle physics and experimentally very well tested, but expected to be broken in some approaches to quantum gravity. It thus becomes pertinent to explore which of the two alternatives is realized: (i) πΆβ’πβ’π symmetry is emergent, so that it is...
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| Main Authors: | , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
6 March, 2026
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| In: |
Physical review letters
Year: 2026, Volume: 136, Issue: 9, Pages: 1-7 |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/frd8-pg3d |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1103/frd8-pg3d Verlag, lizenzpflichtig, Volltext: https://link.aps.org/doi/10.1103/frd8-pg3d 
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| Author Notes: | Astrid Eichhorn, Marc Schiffer |
| Summary: | πΆβ’πβ’π symmetry is at the heart of the standard model of particle physics and experimentally very well tested, but expected to be broken in some approaches to quantum gravity. It thus becomes pertinent to explore which of the two alternatives is realized: (i) πΆβ’πβ’π symmetry is emergent, so that it is restored in the low-energy theory, even if it is broken beyond the Planck scale, (ii) πΆβ’πβ’π symmetry cannot be emergent and must be fundamental, so that any approach to quantum gravity, in which πΆβ’πβ’π is broken, is ruled out. We explore this by calculating the renormalization group flow of πΆβ’πβ’π-violating interactions under the impact of quantum fluctuations of the metric. We find that πΆβ’πβ’π symmetry cannot be emergent and conclude that quantum-gravity approaches must avoid the breaking of πΆβ’πβ’π symmetry. As a specific example, we discover that in asymptotically safe quantum gravity πΆβ’πβ’π symmetry remains intact, if it is imposed as a fundamental symmetry, but it is badly broken at low energies if a tiny amount of πΆβ’πβ’π violation is present in the transplanckian regime. |
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| Item Description: | Gesehen am 11.05.2026 |
| Physical Description: | Online Resource |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/frd8-pg3d |