{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"1cb718200e3c3fbc4aab52a0116b9d4f6e10fcfe1fb5a7cc54044ae969110056","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["496179278bb0be0906f8211788f8b13f4d842ba8658904c8f6747a2872d205a5","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"e9a4793c684560792260a4d8c6f750322817a72ac2163267c260cf79f08ef76f","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":"2","parents":[],"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 $V^{(1/4)} \\sim 1.04 \\times 10^{16}\\ \\mathrm{GeV}\\ (r / 0.01)^{(1/4)}$. 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":"496179278bb0be0906f8211788f8b13f4d842ba8658904c8f6747a2872d205a5","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":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"fea83b272f734ca751f636eb8041e0b7fca8793b74538fc8bc9ebb15c7fe73f9","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"d8ce6dbc406bbb3652fddf87b6b3b6942d9a44fd43ee98b760cf90058ab74909","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"GSHzDp_55RWSg2hq5sofJnKDTH1bcr3_82WqD8d2mKmf-3lFNYkv8e5jXd1SUvzOJj_u5dZOJdugFATWA3OMDQ"},"schema":"pubphys.envelope/1"},"record_hash":"fea83b272f734ca751f636eb8041e0b7fca8793b74538fc8bc9ebb15c7fe73f9","leaf_index":3148}