{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"8fa42d259a0d6dc029e19e17c3b5b5e53a077c5a67aec6771f08eb6811d4f0a1","created":"2026-10-03T07:18:07Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"5dfd9114df94573e43a86cee9022e84adfe84a6546e13b163632159890f6ff6d","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"nuc.qcd-phase-diagram.finite-density-lattice","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Supercomputer calculations of QCD work well at zero net density but fail at high density because of the sign problem (contributions of opposite sign that cancel almost exactly). Without a fix, the dense part of the phase diagram cannot be computed directly.","posed_since":"","precise":"Compute the pressure $P(T,\\mu_{B})$ and the chiral transition line of $2+1$-flavor QCD at physical quark masses for $\\mu_{B}/T$ between 3 and 6 with controlled continuum extrapolation, despite the complex fermion determinant. Answer: $P$ and $T_{\\mathrm{pc}}(\\mu_{B})$ with percent-level uncertainty, by any method (reweighting, Taylor expansion, imaginary $\\mu_{B}$, complex Langevin, Lefschetz thimbles) validated against established results at $\\mu_{B}/T<2$.","problem_ref":null,"references":"","settled_by":"An algorithm with cost polynomial in the lattice volume, validated against established results at $\\mu_B/T < 2$ and applied at $\\mu_B/T = 3\\ \\text{to}\\ 6$.","status_note":"","title":"QCD equation of state at large baryon chemical potential","topic_ref":"8cebfc31c6dfbbabf0b4214c4b9557e92e9b9f0d637fcd43a3fcc8c806d62935"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"0bae407b0890e011a5e7ee604f3882ed101c56f5d030c252ffabe7b711b4f611","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"3bc93dcde06dba8d0c048b3f5bb95ced409d42e12591ddcf39094e9ec3723aae","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"8qC5rLF8OhCstKbF5qQb3ojwScIZjGKtWB5UfiROIqFDbkTCYpdBDU8SrlFL_Cy0n-w4t_LF44YHAtlpMkt6CQ"},"schema":"pubphys.envelope/1"},"record_hash":"0bae407b0890e011a5e7ee604f3882ed101c56f5d030c252ffabe7b711b4f611","leaf_index":1801}