{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"30418a2f54846343e5d20ef7d5e0793c32e69f6c88b7ef0b96cdd15f0d7e98f1","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["c4cb43d215c43c940aa4072dc24598e7759c7f6d8c1f8595cf53c2fc750cc2d4","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"b5d8a305e5a8a4b1cc368261545502738fb6d61c460b923ca8083133dd39a3c1","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"cm.one-over-f-noise.low-frequency-cutoff","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"If the 1/f law held down to zero frequency, the total noise power would grow without limit. No measurement has found where the law stops.","posed_since":"","precise":"The integral of a $1/f$ spectrum diverges logarithmically at both ends, so a physical system needs a lower cutoff $f_{\\min}$, set in the fluctuator picture by the longest relaxation time $\\tau_{\\max} \\sim \\tau_0 \\exp(E_{\\max}/T)$. Measurements over many decades have not found a flattening. Determine $f_{\\min}$ in a specific well-characterized system (metal film or SQUID) and relate it to the fluctuator distribution.","problem_ref":"c4cb43d215c43c940aa4072dc24598e7759c7f6d8c1f8595cf53c2fc750cc2d4","references":"","settled_by":"Long, drift-controlled noise records on a stable device showing a flattening of S(f), compared with an independently measured distribution of fluctuator relaxation times.","status_note":"","title":"Where does 1/f noise stop at low frequency?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"987a8aabcc42e13efc54836a1bd85874c387c16b5052aa78ba8d6bf8aa3abd99","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"13301bb2a8e80421fbc15931a61f8e88a376fe3c40cc465efe71410f624e18e3","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"4z0IR_cdSvnHUB18l7GLKsCZ4tmmhQsgnRiqaEWeYpvu4O1fPlr6aPc3u6tmLfg5S8nC06RwsxTKS8tBcZa1Bw"},"schema":"pubphys.envelope/1"},"record_hash":"987a8aabcc42e13efc54836a1bd85874c387c16b5052aa78ba8d6bf8aa3abd99","leaf_index":2988}