{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"9c944be25153c54e9201001411b5e5a324d42ab705563278de48329f9c79c099","created":"2026-10-03T07:18:02Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"f46ef8d4b78c29507b5b0d59418aa747fd4547eef7adc3472891e7bd02870b35","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"cosmo.inflation.local-non-gaussianity","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"If only one field drove inflation, the primordial ripples should be almost perfectly bell-curve distributed. Several fields would leave a measurable correlation between large and small ripples.","posed_since":"","precise":"Measure the local bispectrum amplitude $f_{\\mathrm{NL}}^{\\mathrm{local}}$; Planck 2018 gives $f_{\\mathrm{NL}}^{\\mathrm{local}} = -0.9 \\pm 5.1$. Single-field inflation predicts $\\left|f_{\\mathrm{NL}}^{\\mathrm{local}}\\right| \\ll 1$ in the squeezed limit; many multi-field models give $\\left|f_{\\mathrm{NL}}^{\\mathrm{local}}\\right| \\ge 1$. An answer is $f_{\\mathrm{NL}}^{\\mathrm{local}}$ with sigma below 0.5 from scale-dependent galaxy bias and CMB.","problem_ref":null,"references":"","settled_by":"SPHEREx and Rubin scale-dependent bias measurements combined with CMB bispectra.","status_note":"","title":"Is primordial local non-Gaussianity of order one?","topic_ref":"690ffa5b73447ba4221a7c006ebf0c4bb3c77c97b6f540e1aa6bb7a20d15d99b"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"5179f7d22b6755e45ae09708563baf580f5989334cc75ecdb05346d448a1e3d8","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"14c1b7d730db4257dec349e78c13dfd02d56f6f29fed18b8d891b787a1ec9f1a","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"YorjXTnNqDmv_MFxfsnNnMVGB4moJinh0WzuLLNanb0cPL1XW26gWG35ynYaR5rxopqG9_omP0-TCGKtY6xGBA"},"schema":"pubphys.envelope/1"},"record_hash":"5179f7d22b6755e45ae09708563baf580f5989334cc75ecdb05346d448a1e3d8","leaf_index":1262}