{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"ea5633527a200c03e6abbd58d233c2dd9687aeec0ea7b925d5b71fc3f85f6670","created":"2026-10-03T07:18:04Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"46751cb516cb5db9a6685ca74afa753b1f5e23186f26c063552cd269bcfccad5","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"grav.strong-field-tests.gw-memory-detection","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"General relativity predicts that a passing gravitational wave leaves detector mirrors permanently displaced, the memory effect, because gravitational waves themselves act as a source of gravity. The effect is small and has not been measured.","posed_since":"1991","precise":"The nonlinear (Christodoulou) memory produces a permanent step in the strain, mainly in the $(\\ell,m) = (2,0)$ mode, with amplitude a small fraction of the peak oscillatory strain for comparable-mass binaries. Determine whether stacking binary black hole events in ground detectors, or single loud events in LISA, detects the memory at more than $3\\sigma$ with the GR amplitude; Lasky et al. (2016) estimated 35 to 90 GW150914-like events for Advanced LIGO. An answer is a detection with the measured amplitude relative to the GR prediction, or an upper limit inconsistent with it.","problem_ref":null,"references":"","settled_by":"A stacked memory search over a catalog of binary black hole events reaching $3\\sigma$ sensitivity to the GR amplitude.","status_note":"A 2026 catalog analysis reports a cumulative log10 Bayes factor of $1.38\\ \\text{plus or minus}\\ 0.79$ in favor of memory, short of detection (arXiv:2607.04909); hierarchical inference finds the memory amplitude consistent with GR but unconstrained (arXiv:2605.27500, 2026).","title":"Detect the nonlinear gravitational-wave memory of black hole mergers","topic_ref":"bc4b175d5b29c50050e1c97990c34784beaa0b526c07994422c4f929f682a68b"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"bd83041264e9b5c2a57675859e1a8d685d865db2bc8e8bf8b621de369f28b7e8","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"6458889fc9d8af74931b5020d32c743b6a258cb06c6caaa0311117f9caa3a168","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"qD7t-w-hC6p7rqdWIgXC2X9jIcxCvxV54gGPokTVIvXVsZLQShf32YUFB8LC175pM-Y9n2NiCdLNkPS1mw__DQ"},"schema":"pubphys.envelope/1"},"record_hash":"bd83041264e9b5c2a57675859e1a8d685d865db2bc8e8bf8b621de369f28b7e8","leaf_index":1510}