{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"948d9fc29f1e77ed499c786b8abeb2ced759dc428c7f03757ca2838cf64cde93","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["073fe63cc8ce83edfa9dd5d85ca5a5bbcc22810208930719e12ee3dcb8ea287a","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"5c64c258a38fe1e897f8aea1816da32201e7b71d12adc1e07734f25b6f21faab","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"bio.active-matter.active-nematic-order","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"Active nematics are layers of elongated self-driven units that line up without a preferred head or tail. Whether such a layer stays orientationally ordered over large distances, or activity always creates enough defects to destroy the order, is disputed.","posed_since":"","precise":"In $2\\mathrm{D}$ dry active nematics (no momentum conservation, e.g. Chate-Ginelli-Montagne-type particle models), determine whether the ordered phase has quasi-long-range orientational order with algebraically decaying correlations, or whether activity unbinds $+1/2$ and $-1/2$ disclinations at any finite activity so that order is lost beyond a finite length. An answer gives the asymptotic form of the orientational correlation function and the defect density versus system size.","problem_ref":"073fe63cc8ce83edfa9dd5d85ca5a5bbcc22810208930719e12ee3dcb8ea287a","references":"","settled_by":"Simulations over several decades of system size measuring orientational correlations and defect density, together with a renormalization-group treatment including defects.","status_note":"","title":"Do two-dimensional dry active nematics keep quasi-long-range order?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"bc5c7859aca9af07908cda9c84715558b7239cc1d00f66545cde159cdecb214f","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"26d9847fb67ed03c33ea1c10056716ed0c280b5f19e0b75e78266bc6f8c945ae","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"zAyzlltHVjmQVnZu9DP0ayrnJVt31zp0CAZ9Jv5bgpGezXvvBX1SVNrUa1CKu33t6QD1cNjTxVx8gde2qPU7Cg"},"schema":"pubphys.envelope/1"},"record_hash":"bc5c7859aca9af07908cda9c84715558b7239cc1d00f66545cde159cdecb214f","leaf_index":2548}