[2403.06053] Spinfoams, $γ$-duality and parity violation in primordial gravitational waves Skip to main content Search Submit Donate Log in Search arXiv Press Enter to search · Advanced search General Relativity and Quantum Cosmology arXiv:2403.06053 (gr-qc) [Submitted on 10 Mar 2024 ( v1 ), last revised 24 Apr 2026 (this version, v2)] Title: Spinfoams, $γ$-duality and parity violation in primordial gravitational waves Authors: Eugenio Bianchi , Monica Rincon-Ramirez View a PDF of the paper titled Spinfoams, $\gamma$-duality and parity violation in primordial gravitational waves, by Eugenio Bianchi and Monica Rincon-Ramirez View PDF HTML (experimental) Abstract: The Barbero-Immirzi parameter $\gamma$ appears as a coupling constant in the spinfoam dynamics of loop quantum gravity. In this work, we highlight that $\gamma$ can be understood as a measure of gravitational parity violation via a duality rotation for the EPRL spinfoam model. We call this property $\gamma$-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 $\gamma$, opening the possibility of its measurement in the semiclassical regime. For a choice of $\gamma$-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. Comments: 18 pages, 2 figures Subjects: General Relativity and Quantum Cosmology (gr-qc) ; Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th) Cite as: arXiv:2403.06053 [gr-qc] (or arXiv:2403.06053v2 [gr-qc] for this version) https://doi.org/10.48550/arXiv.2403.06053 Focus to learn more arXiv-issued DOI via DataCite Submission history From: Eugenio Bianchi [ view email ] [v1] Sun, 10 Mar 2024 00:46:59 UTC (76 KB) [v2] Fri, 24 Apr 2026 18:55:53 UTC (79 KB) Full-text links: Access Paper: View a PDF of the paper titled Spinfoams, $\gamma$-duality and parity violation in primordial gravitational waves, by Eugenio Bianchi and Monica Rincon-Ramirez View PDF HTML (experimental) TeX Source view license Current browse context: gr-qc < prev | next > new | recent | 2024-03 Change to browse by: astro-ph astro-ph.CO hep-th References & Citations INSPIRE HEP NASA ADS Google Scholar Semantic Scholar export BibTeX citation Loading... BibTeX formatted citation × loading... Data provided by: Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer ( What is the Explorer? ) Connected Papers Toggle Connected Papers ( What is Connected Papers? ) Litmaps Toggle Litmaps ( What is Litmaps? ) scite.ai Toggle scite Smart Citations ( What are Smart Citations? ) Code, Data, Media Code, Data and Media Associated with this Article alphaXiv Toggle alphaXiv ( What is alphaXiv? ) Links to Code Toggle CatalyzeX Code Finder for Papers ( What is CatalyzeX? ) DagsHub Toggle DagsHub ( What is DagsHub? ) GotitPub Toggle Gotit.pub ( What is GotitPub? ) Huggingface Toggle Hugging Face ( What is Huggingface? ) ScienceCast Toggle ScienceCast ( What is ScienceCast? ) Demos Demos Replicate Toggle Replicate ( What is Replicate? ) Spaces Toggle Hugging Face Spaces ( What is Spaces? ) Spaces Toggle TXYZ.AI ( What is TXYZ.AI? ) Related Papers Recommenders and Search Tools Link to Influence Flower Influence Flower ( What are Influence Flowers? ) Core recommender toggle CORE Recommender ( What is CORE? ) IArxiv recommender toggle IArxiv Recommender ( What is IArxiv? ) Author Venue Institution Topic About arXivLabs arXivLabs: experimental projects with community collaborators arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website. Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them. Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs . Which authors of this paper are endorsers? | Disable MathJax ( What is MathJax? ) We gratefully acknowledge support from our major funders , member institutions , , and all contributors. About · Help · Contact · Subscribe · Copyright · Privacy · Accessibility · Operational Status (opens in new tab) Major funding support from