{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"64a0fd5c8f2a879684bbe34264c484a471082f05c58e926889f06182f68bc236","created":"2026-10-03T07:17:54Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["3d82953ac83696f999c4420512a4cbb3fbd73816e1206e7274af11f64c42ab47","5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"d3f88452b70f42a5800254fd8e3a09cbad1b6144b957a1b8941b753e4d7ed61c","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"amo.hubbard-simulation.certified-error-budget","kind":"well-posed","literature_status":"open","n":"1","parents":[{"note":"","parent_revision":"3d82953ac83696f999c4420512a4cbb3fbd73816e1206e7274af11f64c42ab47","relation":"special_case"}],"plain":"Once a simulator goes where computers cannot follow, nobody can check its answers by calculation. The task is to bound its errors using only independent calibrations.","posed_since":"","precise":"Choose a point $(U/t, \\delta, T/t)$ where unbiased numerical methods lose control (for example $U/t = 8, \\delta = 0.1, T/t < 0.1$). Using Hamiltonian learning of t, t', U and harmonic confinement, entropy thermometry, and stability bounds, give a certified error bar on the nearest-neighbour spin correlator $C(1,0)$ and on the density. Answer: an error budget with all sources listed and a total below 5%.","problem_ref":null,"references":"","settled_by":"A published error budget combining in-situ Hamiltonian calibration with a proof or numerical bound on how parameter errors propagate to local observables.","status_note":"","title":"Certified accuracy of a Hubbard simulator where numerics fail","topic_ref":"3900d87db48f0080fb068d283e110f5923dafb6ad85daaf4e53a292a8a9304ef"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"a79b09947933ab00507b5c143462d9cfb9b435af311fe0f99293ca1f836a3dc8","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"c2521bc01848310243aa980f3d966ea2500c8eeb182c5cbe3a97ac05a4dfc1f8","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"tP1bkedg9XG8bEoxAqCMXQZQkXDfbA98NEYp3EP6XqzV1CGjjDcC3uAXjbCw2kIpZUJLHabWPa4Ep__KC4G7DA"},"schema":"pubphys.envelope/1"},"record_hash":"a79b09947933ab00507b5c143462d9cfb9b435af311fe0f99293ca1f836a3dc8","leaf_index":462}