{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"7499723b43191172b8be5d35934e9bba6299d2d3c2307394e51a59519d15d85b","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["bf3eb9c4e9da4e24e9a9718dc527904002bc3037a372b0025f71983e5e5453a2","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"6d66fa7d1523fc3277d1b2d066531fadf249d3f141729c045b1b5ff5f89d682e","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":"2","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":"bf3eb9c4e9da4e24e9a9718dc527904002bc3037a372b0025f71983e5e5453a2","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 $1.15 \\times 10^{6}$ to $1.3 \\times 10^{6}$ 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":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"c1395e90154f9ef8abaa993b1f5cb1eab2d3a1560a7d42fbdf65d8e6afc4b786","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"04b21bb28e3540dd2403120f5f5555e458f0f95cf7b789f6c0bdc49bc79846cc","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"W5v9Wyzt6bWAng8wZLh5-NC-3xGmcOVeV0zGkgbABHCXCJcwCqFZ7WELH_I7dAjJ9fRo21096r80xx2f74SIBw"},"schema":"pubphys.envelope/1"},"record_hash":"c1395e90154f9ef8abaa993b1f5cb1eab2d3a1560a7d42fbdf65d8e6afc4b786","leaf_index":3510}