Spinfoams, $γ$-duality and parity violation in primordial gravitational waves
Fuente:
arXiv
Salvato in:
| Autori principali: | , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2024
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866915955566706688 |
|---|---|
| author | Bianchi, Eugenio Rincon-Ramirez, Monica |
| author_facet | Bianchi, Eugenio Rincon-Ramirez, Monica |
| contents | The Barbero-Immirzi parameter $γ$ appears as a coupling constant in the spinfoam dynamics of loop quantum gravity. In this work, we highlight that $γ$ can be understood as a measure of gravitational parity violation via a duality rotation for the EPRL spinfoam model. We call this property $γ$-duality, and we investigate an effective field theory for gravity and a scalar field with the same degree of parity violation. The resulting relation between the coupling constants of parity-even and parity-odd higher-curvature terms in the effective action is determined by $γ$, opening the possibility of its measurement in the semiclassical regime. For a choice of $γ$-dual effective action, we study cosmic inflation and show that the observation of a primordial tensor polarization, together with the tensor tilt and the tensor-to-scalar ratio, provides a measurement of the Barbero-Immirzi parameter and, therefore, of the scale of discreteness of the quantum geometry of space. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2403_06053 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Spinfoams, $γ$-duality and parity violation in primordial gravitational waves Bianchi, Eugenio Rincon-Ramirez, Monica General Relativity and Quantum Cosmology Cosmology and Nongalactic Astrophysics High Energy Physics - Theory The Barbero-Immirzi parameter $γ$ appears as a coupling constant in the spinfoam dynamics of loop quantum gravity. In this work, we highlight that $γ$ can be understood as a measure of gravitational parity violation via a duality rotation for the EPRL spinfoam model. We call this property $γ$-duality, and we investigate an effective field theory for gravity and a scalar field with the same degree of parity violation. The resulting relation between the coupling constants of parity-even and parity-odd higher-curvature terms in the effective action is determined by $γ$, opening the possibility of its measurement in the semiclassical regime. For a choice of $γ$-dual effective action, we study cosmic inflation and show that the observation of a primordial tensor polarization, together with the tensor tilt and the tensor-to-scalar ratio, provides a measurement of the Barbero-Immirzi parameter and, therefore, of the scale of discreteness of the quantum geometry of space. |
| title | Spinfoams, $γ$-duality and parity violation in primordial gravitational waves |
| topic | General Relativity and Quantum Cosmology Cosmology and Nongalactic Astrophysics High Energy Physics - Theory |
| url | https://arxiv.org/abs/2403.06053 |