{"paper":{"title":"The Non-parametric Equation of State Realizes a Generalized Quark-Hadron Crossover","license":"http://creativecommons.org/publicdomain/zero/1.0/","headline":"Non-parametric equation of state construction reveals early stiffening followed by softening in massive neutron stars.","cross_cats":["gr-qc","nucl-th"],"primary_cat":"astro-ph.HE","authors_text":"Shao-Peng Tang, Yi-Zhong Fan, Yong-Jia Huang","submitted_at":"2026-05-09T01:00:23Z","abstract_excerpt":"We propose a non-parametric approach to construct the statistical equation of state (EOS) continuously from the nuclear crust to the asymptotic-freedom regime. The combined requirement of supporting two-solar-mass neutron stars (NSs) with relatively small radii at low masses and of reaching the asymptotically soft pQCD boundary forces a squared-sound-speed ($c_s^2$) peak followed by extended softening, with $c_s^2$ returning toward $1/3$ near $\\sim\\!30\\,n_{\\rm sat}$. Correspondingly, the trace anomaly $\\Delta \\equiv 1/3 - p/\\epsilon$ becomes positive beyond NS densities and approaches the pQCD"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"By measuring the degree of this non-monotonic behavior in the posterior, we find evidence for a hadron-quark phase transition in the cores of the most massive neutron stars. This indicates that the non-perturbative quark matter is intrinsically soft, fundamentally distinguishing it from the stiff scenarios associated with the quark-star picture.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The global thermodynamic constraint is driven by the observationally required stiffening to support two-solar-mass neutron stars with relatively small radii for low-mass neutron stars, combined with the requirement not to overshoot perturbative QCD energy-density bounds.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Non-parametric EOS construction shows non-conformal behavior with evidence for soft quark matter and a hadron-quark phase transition in massive neutron star cores.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Non-parametric equation of state construction reveals early stiffening followed by softening in massive neutron stars.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"b04bb091ac6c86d3fd57f864c4e3231bb8d43ce994864ad2ad6d2a0afe43a556"},"source":{"id":"2605.08584","kind":"arxiv","version":2},"verdict":{"id":"10e6d566-5baf-4be2-a6ba-f6b0c3a76aa1","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-12T01:06:52.816032Z","strongest_claim":"By measuring the degree of this non-monotonic behavior in the posterior, we find evidence for a hadron-quark phase transition in the cores of the most massive neutron stars. This indicates that the non-perturbative quark matter is intrinsically soft, fundamentally distinguishing it from the stiff scenarios associated with the quark-star picture.","one_line_summary":"Non-parametric EOS construction shows non-conformal behavior with evidence for soft quark matter and a hadron-quark phase transition in massive neutron star cores.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The global thermodynamic constraint is driven by the observationally required stiffening to support two-solar-mass neutron stars with relatively small radii for low-mass neutron stars, combined with the requirement not to overshoot perturbative QCD energy-density bounds.","pith_extraction_headline":"Non-parametric equation of state construction reveals early stiffening followed by softening in massive neutron stars."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2605.08584/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"claim_evidence","ran_at":"2026-05-20T09:22:01.960485Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"ai_meta_artifact","ran_at":"2026-05-19T22:38:16.517287Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_title_agreement","ran_at":"2026-05-19T14:31:18.272222Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-19T10:59:34.415993Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"657abbb38bc0c0ff44d1007ff8663fe7ce875e9645fc9ad1ecefd82d36d26d32"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"5f4f2e8e3ca48814bea7223c1fc97db486c1974d778a3d8f1b59474f659f90fc"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}