{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"0ba6b7c405686e6626d96c314693a3cb69d88f2cd71537411295c45a8e8151d2","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b","d887532c1f6edd1e8747472a7d74fa9c48c33c7fed4ce231740d5f992602181a"],"salt":"f772bb5431dad55be1e618d45f157d46a855af99bbb8ca04d49e220d77e0b175","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.strange-metals.planckian-universality","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"Data in several materials suggest the electron scattering rate equals temperature times a fixed combination of Boltzmann's and Planck's constants; it is unknown whether this is a true limit.","posed_since":"2004","precise":"With $\\hbar/\\tau = \\alpha k_B T$ extracted from the T-linear resistivity slope and the independently measured effective mass and carrier density, test whether $\\alpha = 1$ within error across strange metals and whether any metal sustains $\\alpha >> 1$. An answer is a proof of a bound on the transport scattering rate within a defined class of models, or a material with reliably measured $\\alpha$ well above 1.","problem_ref":"d887532c1f6edd1e8747472a7d74fa9c48c33c7fed4ce231740d5f992602181a","references":"","settled_by":"Quantum-oscillation or specific-heat masses combined with resistivity slopes in many materials, plus a theorem bounding $\\hbar/\\tau$ in a stated class of models.","status_note":"Analyses of several hole-doped cuprates (2019) gave $\\alpha \\sim 1$; no rigorous bound on the transport rate is known.","title":"Is the Planckian scattering rate universal, and is it a bound?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"89062196cf5cdc670596c79c637134903496c1952c7844ebcd0e64eb46188a11","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"820650e58028b4c86baaf2b3ff1226940bbad0d427447a3b9798de213be85282","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"JpL4zNJ-Ase_C3fnsTSXGWq3cNk5zx66vuc7UDcbWmYMoEoEwsiUqEyBTifDkFy-QvvFc69ooO12JU3FECF9Cw"},"schema":"pubphys.envelope/1"},"record_hash":"89062196cf5cdc670596c79c637134903496c1952c7844ebcd0e64eb46188a11","leaf_index":3062}