{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"f29c5b150ebd048d416dd3502f4a64d8cb6b5502b4482d5c380b3d8447679551","created":"2026-10-03T07:18:07Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"a77c55333194385be813260e5713670cc31460edb18fbc8fb669bc0bc8d737a6","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"nuc.neutron-star-matter.quark-cores","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"At the centre of the heaviest neutron stars, protons and neutrons may dissolve into free quarks. Whether this happens is not known.","posed_since":"","precise":"For a neutron star near $M_{\\mathrm{TOV}}$, determine whether the central density exceeds the onset of deconfined quark matter, diagnosed by the polytropic index $\\gamma=d\\ln P/d\\ln\\epsilon$ approaching its conformal value 1 and the normalized trace anomaly $(\\epsilon-3P)/(3\\epsilon)$ approaching 0, where $\\epsilon$ is energy density. Answer: yes or no, with posterior probability given all astrophysical data and perturbative QCD limits.","problem_ref":null,"references":"","settled_by":"Precise radii for two-solar-mass stars together with post-merger gravitational-wave frequencies sensitive to a phase transition.","status_note":"Annala et al. (Nature Physics 2020; Nature Communications 2023) inferred near-conformal matter in maximal-mass cores with high probability, but the conclusion depends on how the hadronic and quark phases are defined.","title":"Do the heaviest neutron stars have quark-matter cores?","topic_ref":"dc9703fcc2930752e3222472fa4f0774fcc6cb72d19c4033b77e3e2b58d0fcb3"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"9141b3a66f7e5e6ed393378173eb93fee633a2df22f08ad925ebb8901aed99d0","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"b4cb7a8a1e2a763b0a6960f6e18d7429eefdacf5aca386718bcf638134265ad0","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"hBApJ5rJNeEZ_cxgb1gccBZzbdwtjuOgRbUlu2058yQRLN3oPKudKbhSIfp3a_lJhT5JKWtuTRL5uF1WMXlTCQ"},"schema":"pubphys.envelope/1"},"record_hash":"9141b3a66f7e5e6ed393378173eb93fee633a2df22f08ad925ebb8901aed99d0","leaf_index":1781}