{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"70fdcde8fc10fd37a5aead7d6955c81c649d8e080d9a6c17c9debaf651fdf3e7","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["140b021e704aeaafa181884dad7d2bffc67d70cc4cc34bf112245d74ea7a16fd","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"03b4bd4e519c11290f769bec0cf75e0634a3dc0e19b7e3cc77ea683de2f582e9","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"grav.strong-field-tests.kerr-spectroscopy-precision","kind":"well-posed","literature_status":"partially-resolved","n":"2","parents":[],"plain":"A newly merged black hole rings like a bell at frequencies fixed by its mass and spin if it is a Kerr black hole. Measuring two or more tones in one event tests this directly.","posed_since":"2004","precise":"For merger remnants, measure the complex frequencies of at least two independent quasinormal modes, for example $(l,m,n) = (2,2,0)$ together with $(2,2,1)$, $(3,3,0)$ or $(4,4,0)$, and constrain the fractional deviations $\\delta f$ and $\\delta \\tau$ from Kerr values for a common mass and spin. The target is $\\mid\\delta f\\mid, \\mid\\delta \\tau\\mid$ below 0.01. An answer is the measured deviations with uncertainties from a catalog of events.","problem_ref":"140b021e704aeaafa181884dad7d2bffc67d70cc4cc34bf112245d74ea7a16fd","references":"","settled_by":"Multi-mode ringdown measurements with percent-level frequency and damping-time constraints from next-generation ground detectors or LISA.","status_note":"GW250114 gave two modes at $4.1\\,\\sigma$ with the overtone frequency consistent with Kerr to plus or minus $30\\%$ and the damping rate unconstrained (LIGO-Virgo-KAGRA 2025).","title":"Do remnant black hole ringdown tones match Kerr at percent precision?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"19e516fa5abc2d851dac1cfed12223c54c95b36d0420c1e3fa27e5ccd554599d","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"d0faa6e3e34462c2904375dd5336da09e447acfd05a68c928771b902c2da560c","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"9e2rkS3vphSEWPBw_H1R7Dj0BDvbGib6__hewkmh8UYQh3K8Yzyd_11I5DzspoaTu3ehXke2hP8XqHFcwVlnCQ"},"schema":"pubphys.envelope/1"},"record_hash":"19e516fa5abc2d851dac1cfed12223c54c95b36d0420c1e3fa27e5ccd554599d","leaf_index":3310}