{"paper":{"title":"Black Hole Spectroscopy and Tests of General Relativity with GW250114","license":"http://creativecommons.org/licenses/by/4.0/","headline":"The loudest gravitational wave event GW250114 confirms the Kerr nature of the remnant black hole and general relativity to few-percent precision in a single detection.","cross_cats":["astro-ph.HE"],"primary_cat":"gr-qc","authors_text":"the KAGRA Collaboration, The LIGO Scientific Collaboration, the Virgo Collaboration","submitted_at":"2025-09-09T19:17:32Z","abstract_excerpt":"The binary black hole signal GW250114, the loudest gravitational wave detected to date, offers a unique opportunity to test Einstein's general relativity (GR) in the high-velocity, strong-gravity regime and probe whether the remnant conforms to the Kerr metric. Upon perturbation, black holes emit a spectrum of damped sinusoids with specific, complex frequencies. Our analysis of the post-merger signal shows that at least two quasi-normal modes are required to explain the data, with the most damped remaining statistically significant for about one cycle. We probe the remnant's Kerr nature by con"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"These results constitute the most stringent single-event verification of GR and the Kerr nature of black holes to date, with the quadrupolar frequency bounded to within a few percent of the GR prediction and the spectroscopic pattern matching Kerr to tens of percent.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The analysis assumes that the post-merger signal is accurately described by linear perturbation theory on a Kerr background and that the numerical-relativity simulations used for comparison are free of systematic modeling errors at the precision needed for the reported constraints.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"GW250114 data confirm the remnant is consistent with a Kerr black hole and bound the dominant quadrupolar mode frequency to within a few percent of the GR prediction, with constraints tighter than prior multi-event catalogs.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"The loudest gravitational wave event GW250114 confirms the Kerr nature of the remnant black hole and general relativity to few-percent precision in a single detection.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"ba1edbc6bbb3fcb0bfc9f35bf2b90700d8ed359d0174f1a974ac4059ba9ab180"},"source":{"id":"2509.08099","kind":"arxiv","version":1},"verdict":{"id":"b0bd00c7-82cf-42b2-8481-1803c2e73e74","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-15T16:40:44.930117Z","strongest_claim":"These results constitute the most stringent single-event verification of GR and the Kerr nature of black holes to date, with the quadrupolar frequency bounded to within a few percent of the GR prediction and the spectroscopic pattern matching Kerr to tens of percent.","one_line_summary":"GW250114 data confirm the remnant is consistent with a Kerr black hole and bound the dominant quadrupolar mode frequency to within a few percent of the GR prediction, with constraints tighter than prior multi-event catalogs.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The analysis assumes that the post-merger signal is accurately described by linear perturbation theory on a Kerr background and that the numerical-relativity simulations used for comparison are free of systematic modeling errors at the precision needed for the reported constraints.","pith_extraction_headline":"The loudest gravitational wave event GW250114 confirms the Kerr nature of the remnant black hole and general relativity to few-percent precision in a single detection."},"references":{"count":229,"sample":[{"doi":"","year":null,"title":":H ′(220)] relative to the 1% FAP threshold evaluated on background noise, while the green plus indicate the offset ofD[H(220+221+222) :H ′(220+221)] relative to its corresponding threshold. For each ","work_id":"0c0d4eac-933c-42ef-bd7f-243e91ca2ae4","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"Similarly, when the three-mode modelH(220+221+222) is preferred overH ′(220+221) withD>D 1% from starting times 1t Mf to 5t Mf, we observe a reduction inp(M IMR f , χIMR f )","work_id":"296f6b33-76c5-4fa6-87f2-532e997360a6","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2015,"title":"Advanced LIGO","work_id":"b93186e6-8d0a-440a-aa48-9de6dbff57b9","ref_index":3,"cited_arxiv_id":"1411.4547","is_internal_anchor":true},{"doi":"","year":2015,"title":"Advanced Virgo: a 2nd generation interferometric gravitational wave detector","work_id":"29d52a5a-6fd3-471b-8fec-d17c29cf9026","ref_index":5,"cited_arxiv_id":"1408.3978","is_internal_anchor":true},{"doi":"","year":2021,"title":"Akutsuet al.(KAGRA), Overview of KAGRA: Detector design and construction history, PTEP2021, 05A101 (2021), arXiv:2005.05574 [physics.ins-det]","work_id":"5d6cbaec-f994-4631-bca0-649752990e3b","ref_index":6,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":229,"snapshot_sha256":"e178a3c2d8befc37337881f746eb915c30346f929b628ae8388803b3ca2ad195","internal_anchors":71},"formal_canon":{"evidence_count":2,"snapshot_sha256":"3745e808841c9c2ecccd1c778b5fd45d91757ef4081a68f2f7e60ae58d69daab"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}