Expanding Our Horizons: Rethinking Gravity's Role in the Quantum-to-Classical Transition

[2604.01283] Expanding Our Horizons: Rethinking Gravity's Role in the Quantum-to-Classical Transition Skip to main content Search Submit Donate Log in General Relativity and Quantum Cosmology arXiv:2604.01283 (gr-qc) [Submitted on 1 Apr 2026 ( v1 ), last revised 24 Aug 2026 (this version, v2)] Title: Expanding Our Horizons: Rethinking Gravity's Role in the Quantum-to-Classical Transition Authors: Aurora Ireland View PDF HTML (experimental) Abstract: The origin of cosmic structure is widely regarded as quantum, yet the Universe today appears classical. Standard lore attributes this to a "quantum-to-classical" transition on super-horizon scales during inflation. Gravity plays a central role: super-horizon dynamics squeeze quantum states, while the cosmological horizon enforces a system-environment split, leading to decoherence. But are these mechanisms always sufficient? We revisit this question, identifying assumptions and limitations in conventional arguments. We highlight recent work showing that beyond slow roll, non-linear dynamics of cosmological perturbations can generate and amplify quantum coherence at the closed-system level. Preliminary results further suggest that, for the minimal irreducible contribution to decoherence coming from stochastic kicks at the coarse-graining scale, the rate of coherence generation can outpace the decoherence rate. This raises the possibility that signatures of a quantum origin may persist in cosmic structure. We propose a phase-space analysis based on the Wigner function as a concrete route to identifying and probing such signatures. Comments: Essay written for the Gravity Research Foundation 2026 Awards for Essays on Gravitation; v2: updated results Subjects: General Relativity and Quantum Cosmology (gr-qc) ; Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th) Cite as: arXiv:2604.01283 [gr-qc] (or arXiv:2604.01283v2 [gr-qc] for this version) https://doi.org/10.48550/arXiv.2604.01283 Focus to learn more arXiv-issued DOI via DataCite Submission history From: Aurora Ireland [ view email ] [v1] Wed, 1 Apr 2026 18:00:27 UTC (705 KB) [v2] Mon, 24 Aug 2026 18:00:03 UTC (706 KB) Full-text links: Access Paper: View PDF HTML (experimental) TeX Source view license Current browse context: gr-qc < prev | next > new | recent | 2026-04 Change to browse by: astro-ph astro-ph.CO hep-th References & Citations INSPIRE HEP SciX Google Scholar Semantic Scholar export BibTeX citation 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)

Related documents

• Expanding Our Horizons: Rethinking Gravity's Role in the Quantum-to-Classical Transition#670544
• Have we Lost Spacetime on the Way? Narrowing the Gap between General Relativity and Quantum Gravity#747636
• What Becomes of Kinematics and Dynamics When Spacetime Goes Missing?#690482
• The Possibility That Tension Is Smaller Than the Graviton#109070
• P2.08 Recursive Reality Project - Convergent Evidence from Quantum Gravity and the Philosophy of Physics#73759