{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"74423589bd8be52483dcbe37cffde9877d14f7f4521597919be43b8dcac166cf","created":"2026-10-03T07:18:02Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","dc234507b7a27d76c5acfb538607a35e63ce34bfbbbc5009da3ce2d1efe09669"],"salt":"0267fa3eea123d282ae69833a84fb96f3765bb74eafe8a2b388f58ec83742e10","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cosmo.quantum-cosmology.bounce-alternatives","kind":"well-posed","literature_status":"open","n":"1","parents":[{"note":"","parent_revision":"dc234507b7a27d76c5acfb538607a35e63ce34bfbbbc5009da3ce2d1efe09669","relation":"special_case"}],"plain":"Instead of inflation, the universe might have contracted and then bounced into expansion. Such models must avoid unstable or unphysical fields at the bounce while matching observations.","posed_since":"","precise":"Construct a geodesically complete bouncing or ekpyrotic cosmology, free of ghost and gradient instabilities and under effective-field-theory control through the bounce, that predicts $n_s = 0.974 \\pm 0.003$, $r < 0.036$ and $\\mid f_{\\mathrm{NL}}^{\\mathrm{local}}\\mid < 10$. Answer yes with an explicit model, or no with a no-go theorem for a defined class.","problem_ref":null,"references":"","settled_by":"An explicit stable model with computed spectra, or a no-go theorem covering scalar-tensor bounces.","status_note":"","title":"Can a nonsingular bounce reproduce all observed primordial spectra?","topic_ref":"316c65cff3d448b6835a5fe0d3c6263860b268b7d9bf5157ff20e9877ce5ed6e"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"01e2c11721929d1eb93984cc7b587044b3481f0dc1118ed415f061a003c443ef","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"96a5b13453babe19036a81d6f4b17da3d3ac64baf3d218defb0ea389a39a2823","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"rcPNlbxAdaV25Uk8PO-mOVVkjDC9Y5eQ_GvXLW2r_dJKEsK0u-8_-18x-aWpcG-9SqeXQ6nszOJKZwAPD583Dg"},"schema":"pubphys.envelope/1"},"record_hash":"01e2c11721929d1eb93984cc7b587044b3481f0dc1118ed415f061a003c443ef","leaf_index":1274}