{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"120e8a7bb1d19a6fe8d5707a72566c1f381405810e9528af4289c8b657531578","created":"2026-10-03T07:17:57Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"69bd60ab19abd5c3fd12901f572d68ab795fa5c3fbfcb67f1e5ac34986f6b003","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"bio.polymer-dynamics.ring-melt-relaxation","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"Ring-shaped polymers have no ends, so they cannot slide out of entanglements end-first as linear chains do. How a melt of rings flows and relaxes stress is still unclear.","posed_since":"","precise":"For melts of nonconcatenated, unknotted rings of N monomers with $N / N_e >> 1$ ($N_e$ the entanglement length), determine the scaling of the zero-shear viscosity $\\eta_0(N)$ and of the stress-relaxation modulus $G(t)$ (power law $G(t) \\sim t^{-\\alpha}$ versus a plateau), the role of ring-ring threading, and whether threading produces a topological glass for large N. An answer is a theory agreeing with simulations to $N / N_e > 50$ and with experiments on purified rings.","problem_ref":null,"references":"","settled_by":"Consistent $\\eta_{0}(N)$ exponents and $G(t)$ shapes from purified-ring experiments and long-ring simulations, explained by a theory that predicts or excludes a threading-induced glass.","status_note":"Simulations and experiments on purified rings report power-law stress relaxation; whether threading produces a topological glass at large N remains disputed (2026).","title":"How unconcatenated ring polymers relax stress in a melt","topic_ref":"aeb1d914c5245c3ac0eb6390c11efb8e31b123b88f6954758542aa7f4dbb81e4"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"7355648dcd29b24acd553ef364bb2e4a855425d4056ffc4efb448fd11cf8bb5b","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"359a85342daf48c00d4ca63270282b91375f620acacac207a5b7fbbd93adc974","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"so0CWsuSn7c8f_Fhl0rLb-ZRglUb3YogXmRfYJ_9Wtv-VgHOzi5Yb5ty8tyXVjBqoyLRK2fn7hug3KbazZaVBA"},"schema":"pubphys.envelope/1"},"record_hash":"7355648dcd29b24acd553ef364bb2e4a855425d4056ffc4efb448fd11cf8bb5b","leaf_index":824}