{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"1a04c8e3973dd77b06858875758746b37fc97b3788ed7995f8011747a6f2a917","created":"2026-10-03T07:18:07Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"17f464a8d8d65d75bc6dd5e9b3c761248d63307ed34cee19c02be09b58ffd4f3","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"nuc.neutron-star-matter.pressure-density-relation","kind":"well-posed","literature_status":"partially-resolved","n":"1","parents":[],"plain":"How hard dense matter pushes back sets how large a neutron star of a given mass is. The goal is to pin down this pressure from star observations combined with theory.","posed_since":"","precise":"Determine the pressure $P(n)$ of cold beta-equilibrated matter for baryon density n between $2\\,n_0$ and $8\\,n_0$ ($n_0 = 0.16\\,\\mathrm{fm}^{-3}$) with 10 percent uncertainty, combining chiral EFT below about $2\\,n_0$, perturbative QCD above about $40\\,n_0$, pulsar masses, NICER (X-ray timing telescope) radii and gravitational-wave tidal deformabilities. Answer: a $P(n)$ band with stated priors.","problem_ref":null,"references":"","settled_by":"Radius measurements with 2 percent precision for stars of 1.4 and 2.0 solar masses, together with post-merger gravitational-wave spectra from next-generation detectors.","status_note":"Combined analyses since 2018 constrain the radius of a 1.4 solar-mass star to roughly 1.15e6 to 1.3e6 cm, while the pressure above about $3 n_{0}$ remained weakly constrained as of 2026.","title":"Pressure of neutron-star matter between two and eight times nuclear density","topic_ref":"dc9703fcc2930752e3222472fa4f0774fcc6cb72d19c4033b77e3e2b58d0fcb3"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"bf3eb9c4e9da4e24e9a9718dc527904002bc3037a372b0025f71983e5e5453a2","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"69293538d28701fac7112b346fd3aef7787ea5cc8fc7ae804ff751cf771c709b","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"eAXhzG4QfeS_iI0tATDZv3P3Qaywf9H8HLF3vr0i2nO-Bdw4Otqs_jPSvUewdlAE1-UxlDVWiZnQtpG6WG75Cg"},"schema":"pubphys.envelope/1"},"record_hash":"bf3eb9c4e9da4e24e9a9718dc527904002bc3037a372b0025f71983e5e5453a2","leaf_index":1780}