{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"7406df75d0803ddd8edaacf81372bd6093fe5bb182cc73d13373be2b506e9e52","created":"2026-10-03T07:18:02Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","dc234507b7a27d76c5acfb538607a35e63ce34bfbbbc5009da3ce2d1efe09669"],"salt":"9183bafcfcb01e6a6b34f4b4064100446e90a88bb06340321efed5ad444045ba","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"cosmo.inflation.tensor-to-scalar-ratio","kind":"well-posed","literature_status":"open","n":"1","parents":[{"note":"","parent_revision":"dc234507b7a27d76c5acfb538607a35e63ce34bfbbbc5009da3ce2d1efe09669","relation":"special_case"}],"plain":"Inflation would have shaken space itself and left gravitational waves that imprint a twisting pattern on the polarization of the cosmic microwave background. Their strength would reveal the energy at which inflation happened.","posed_since":"","precise":"Measure the tensor-to-scalar ratio r at pivot $k = 0.05\\ \\mathrm{Mpc}^{-1}$, which fixes the inflation energy scale $V^{(1/4)} \\sim 1.04e16\\ \\mathrm{GeV}\\ (r / 0.01)^{(1/4)}$. Current bound $r < 0.036$ (95 percent, BICEP/Keck 2021), $r < 0.038$ with ACT DR6. An answer is a detection or a bound $r < 0.001$ after delensing and foreground separation.","problem_ref":null,"references":"","settled_by":"BICEP Array, South Pole Observatory, Simons Observatory and LiteBIRD B-mode measurements reaching $\\sigma(r) \\sim 0.001$.","status_note":"South Pole Observatory projections (2026) aim at $\\sigma(r) \\sim 0.001$ by about 2034 (moderate confidence).","title":"What is the amplitude of primordial gravitational waves?","topic_ref":"690ffa5b73447ba4221a7c006ebf0c4bb3c77c97b6f540e1aa6bb7a20d15d99b"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"496179278bb0be0906f8211788f8b13f4d842ba8658904c8f6747a2872d205a5","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"25c3c64129f0b317f0aad7a2e2c1b54bb99f6c7aff5c67193053b9a01ab202c4","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"Fi5p9w3ytQGZ6YtarbHxEP-NwZM9yNAz1YbEwk1ZXTUmsjlzoFMFJ4iKLk3sQdGXLg9PvhZ9MFKgG0xdaOToCQ"},"schema":"pubphys.envelope/1"},"record_hash":"496179278bb0be0906f8211788f8b13f4d842ba8658904c8f6747a2872d205a5","leaf_index":1263}