Purely virtual extension of quantum field theory for gauge invariant fields: quantum gravity
Abstract Quantum gravity is extended to include purely virtual “cloud sectors”, which allow us to define a complete set of point-dependent observables, including a gauge invariant metric and gauge invariant matter fields, and calculate their off-shell correlation functions perturbatively. The ordina...
| Main Author: | |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2023-11-01
|
| Series: | European Physical Journal C: Particles and Fields |
| Online Access: | https://doi.org/10.1140/epjc/s10052-023-12220-4 |
| _version_ | 1797233320971468800 |
|---|---|
| author | Damiano Anselmi |
| author_facet | Damiano Anselmi |
| author_sort | Damiano Anselmi |
| collection | DOAJ |
| description | Abstract Quantum gravity is extended to include purely virtual “cloud sectors”, which allow us to define a complete set of point-dependent observables, including a gauge invariant metric and gauge invariant matter fields, and calculate their off-shell correlation functions perturbatively. The ordinary on-shell correlation functions and the S matrix elements are unaffected. Each extra sector is made of a cloud field, its anticommuting partner, a “cloud-fixing” function and a cloud Faddeev-Popov determinant. The additional fields are purely virtual, to ensure that no ghosts propagate. The extension is unitary. In particular, the off-shell, diagrammatic version of the optical theorem holds. The one-loop two-point functions of dressed scalars, vectors and gravitons are calculated. Their absorptive parts are positive, cloud independent and gauge independent, while they are unphysical if non purely virtual clouds are used. We illustrate the differences between our approach to the problem of finding a complete set of observables in quantum gravity and other approaches available in the literature. |
| first_indexed | 2024-03-09T14:58:04Z |
| format | Article |
| id | doaj.art-5628fb8b4b614767a8401cd28d8608df |
| institution | Directory Open Access Journal |
| issn | 1434-6052 |
| language | English |
| last_indexed | 2024-04-24T16:14:18Z |
| publishDate | 2023-11-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | European Physical Journal C: Particles and Fields |
| spelling | doaj.art-5628fb8b4b614767a8401cd28d8608df2024-03-31T11:30:47ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60522023-11-01831111710.1140/epjc/s10052-023-12220-4Purely virtual extension of quantum field theory for gauge invariant fields: quantum gravityDamiano Anselmi0Dipartimento di Fisica “E.Fermi”, Università di PisaAbstract Quantum gravity is extended to include purely virtual “cloud sectors”, which allow us to define a complete set of point-dependent observables, including a gauge invariant metric and gauge invariant matter fields, and calculate their off-shell correlation functions perturbatively. The ordinary on-shell correlation functions and the S matrix elements are unaffected. Each extra sector is made of a cloud field, its anticommuting partner, a “cloud-fixing” function and a cloud Faddeev-Popov determinant. The additional fields are purely virtual, to ensure that no ghosts propagate. The extension is unitary. In particular, the off-shell, diagrammatic version of the optical theorem holds. The one-loop two-point functions of dressed scalars, vectors and gravitons are calculated. Their absorptive parts are positive, cloud independent and gauge independent, while they are unphysical if non purely virtual clouds are used. We illustrate the differences between our approach to the problem of finding a complete set of observables in quantum gravity and other approaches available in the literature.https://doi.org/10.1140/epjc/s10052-023-12220-4 |
| spellingShingle | Damiano Anselmi Purely virtual extension of quantum field theory for gauge invariant fields: quantum gravity European Physical Journal C: Particles and Fields |
| title | Purely virtual extension of quantum field theory for gauge invariant fields: quantum gravity |
| title_full | Purely virtual extension of quantum field theory for gauge invariant fields: quantum gravity |
| title_fullStr | Purely virtual extension of quantum field theory for gauge invariant fields: quantum gravity |
| title_full_unstemmed | Purely virtual extension of quantum field theory for gauge invariant fields: quantum gravity |
| title_short | Purely virtual extension of quantum field theory for gauge invariant fields: quantum gravity |
| title_sort | purely virtual extension of quantum field theory for gauge invariant fields quantum gravity |
| url | https://doi.org/10.1140/epjc/s10052-023-12220-4 |
| work_keys_str_mv | AT damianoanselmi purelyvirtualextensionofquantumfieldtheoryforgaugeinvariantfieldsquantumgravity |