{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"1d57cabefd2d9414421fdd95a2f52594acf523b8b4d5838cd6c518c3975a927e","created":"2026-10-03T07:18:03Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"42fad2f6b00d4180eb3f538baed87b7abd34578a969fe82ba3b83c325fa6da12","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"fluid.quantum-turbulence.2d-inverse-cascade","kind":"well-posed","literature_status":"partially-resolved","n":"1","parents":[],"plain":"Flat superfluids made of ultracold atoms have been seen to gather same-direction vortices into giant clusters, as predicted by Lars Onsager, a theoretical chemist and physicist. Simulations show energy flowing steadily to large scales under stirring, but no experiment has yet shown such a lasting flow of energy.","posed_since":"","precise":"In a 2D compressible Bose-Einstein condensate described by the Gross-Pitaevskii equation, forced at scales of a few healing lengths or larger, does a stationary inverse energy cascade with $E(k) \\sim k^{-5/3}$ and constant upscale flux over a decade form in experiment, and how do compressibility, sound emission, vortex-antivortex annihilation and damping set the conditions for it? Answer: yes or no for given conditions, with the measured flux.","problem_ref":null,"references":"","settled_by":"A forced $2\\mathrm{D}$ condensate experiment showing a stationary $k^{-5/3}$ range with measured constant upscale flux over a decade, or a demonstration that none forms under stated conditions.","status_note":"Gross-Pitaevskii simulations with stirred obstacles report an inverse cascade with a $k^{-5/3}$ range (Reeves, Billam, Anderson, Bradley, PRL 2013); Onsager clusters were observed in decaying experiments (2019); no experiment has shown a stationary forced cascade with measured constant upscale flux.","title":"Steady inverse energy cascade in forced two-dimensional quantum fluids","topic_ref":"cfe86b913c28db61b8da643149e508af2654c7237f0b6efa1efaa4c2c1fe95b1"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"f43bde12d46c4157a5e5ebad676baa754d06a7056dcc4aadcfa5e1533a121964","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"654a8741a717360d30fca2af593825a8ec018398dcb996bd57c792d4ba5cbe71","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"Gi4YRXqQlx7a2_IGzwZroFBc9O3yWTBCKkPhayRSnvm7KiZHj12kkqLo-OouHeEExair-ilAXfZNYF75L3yCBA"},"schema":"pubphys.envelope/1"},"record_hash":"f43bde12d46c4157a5e5ebad676baa754d06a7056dcc4aadcfa5e1533a121964","leaf_index":1419}