{"id":"https://openalex.org/W7212290200","doi":"https://doi.org/10.48550/arxiv.2609.11908","title":"Theoretical Aspects of Direct Waves in Kerr Black Holes: Pole-Splitting Method for Ringdown Analysis","display_name":"Theoretical Aspects of Direct Waves in Kerr Black Holes: Pole-Splitting Method for Ringdown Analysis","publication_year":2026,"publication_date":"2026-09-10","ids":{"openalex":"https://openalex.org/W7212290200","doi":"https://doi.org/10.48550/arxiv.2609.11908"},"language":"en","primary_location":{"id":"pmh:oai:arXiv.org:2609.11908","doi":null,"is_oa":true,"landing_page_url":"https://arxiv.org/abs/2609.11908","pdf_url":"https://arxiv.org/pdf/2609.11908","source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"text"},"volume":null,"type":"preprint","is_traditional":true,"indexed_in":["arxiv","datacite"],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"https://arxiv.org/pdf/2609.11908","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5122242982","display_name":"Nao Nakamoto","orcid":"https://orcid.org/0009-0001-0646-0476","observed_orcids":["https://orcid.org/0009-0001-0646-0476"]},"institutions":[{"id":"https://openalex.org/I22299242","display_name":"Kyoto University","ror":"https://ror.org/02kpeqv85","country_code":"JP","type":"education","lineage":["https://openalex.org/I22299242"]}],"countries":["JP"],"is_corresponding":false,"raw_author_name":"Nakamoto, Nao","raw_affiliation_strings":["Department of Physics , Kyoto University , Kyoto 606-8502 , Japan"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Physics , Kyoto University , Kyoto 606-8502 , Japan","institution_ids":["https://openalex.org/I22299242"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5088682748","display_name":"Naritaka Oshita","orcid":"https://orcid.org/0000-0002-8799-1382","observed_orcids":["https://orcid.org/0000-0002-8799-1382"]},"institutions":[{"id":"https://openalex.org/I4210110652","display_name":"RIKEN","ror":"https://ror.org/01sjwvz98","country_code":"JP","type":"facility","lineage":["https://openalex.org/I4210110652"]},{"id":"https://openalex.org/I916559398","display_name":"Kindai University","ror":"https://ror.org/05kt9ap64","country_code":"JP","type":"education","lineage":["https://openalex.org/I916559398"]}],"countries":["JP"],"is_corresponding":false,"raw_author_name":"Oshita, Naritaka","raw_affiliation_strings":["Department of Physics , Kindai University , Osaka 577-8502 , Japan","RIKEN iTHEMS , Wako , Saitama , 351-0198 , Japan"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Physics , Kindai University , Osaka 577-8502 , Japan","institution_ids":["https://openalex.org/I916559398"]},{"raw_affiliation_string":"RIKEN iTHEMS , Wako , Saitama , 351-0198 , Japan","institution_ids":["https://openalex.org/I4210110652"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5062601283","display_name":"H. Takeda","orcid":"https://orcid.org/0000-0001-9937-2557","observed_orcids":["https://orcid.org/0000-0001-9937-2557"]},"institutions":[{"id":"https://openalex.org/I22299242","display_name":"Kyoto University","ror":"https://ror.org/02kpeqv85","country_code":"JP","type":"education","lineage":["https://openalex.org/I22299242"]},{"id":"https://openalex.org/I4405287401","display_name":"The Hakubi Center for Advanced Research, Kyoto University","ror":"https://ror.org/052hjm151","country_code":"JP","type":"facility","lineage":["https://openalex.org/I22299242","https://openalex.org/I4405287401"]}],"countries":["JP"],"is_corresponding":false,"raw_author_name":"Takeda, Hiroki","raw_affiliation_strings":["Department of Physics , Kyoto University , Kyoto 606-8502 , Japan","The Hakubi Center for Advanced Research , Kyoto University , Kyoto 606-8501 , Japan"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Physics , Kyoto University , Kyoto 606-8502 , Japan","institution_ids":["https://openalex.org/I22299242"]},{"raw_affiliation_string":"The Hakubi Center for Advanced Research , Kyoto University , Kyoto 606-8501 , Japan","institution_ids":["https://openalex.org/I4405287401"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":4,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":null,"has_fulltext":true,"cited_by_count":3,"citation_normalized_percentile":null,"cited_by_percentile_year":null,"biblio":{"volume":null,"issue":null,"first_page":null,"last_page":null},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10463","display_name":"Pulsars and Gravitational Waves Research","score":0.9843999743461609,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10463","display_name":"Pulsars and Gravitational Waves Research","score":0.9843999743461609,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10025","display_name":"Black Holes and Theoretical Physics","score":0.0066999997943639755,"subfield":{"id":"https://openalex.org/subfields/3106","display_name":"Nuclear and High Energy Physics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10744","display_name":"Astrophysical Phenomena and Observations","score":0.006300000008195639,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/direct-wave","display_name":"direct wave","score":0.9660000205039978},{"id":"https://openalex.org/keywords/rotating-black-holes","display_name":"rotating black holes","score":0.9570000171661377},{"id":"https://openalex.org/keywords/extreme-mass-ratio-inspirals","display_name":"extreme mass ratio inspirals","score":0.8610000014305115},{"id":"https://openalex.org/keywords/quasinormal-modes","display_name":"quasinormal modes","score":0.949999988079071},{"id":"https://openalex.org/keywords/ringdown","display_name":"ringdown","score":0.6200000047683716},{"id":"https://openalex.org/keywords/ergoregion","display_name":"ergoregion","score":0.7870000004768372},{"id":"https://openalex.org/keywords/apparent-horizon","display_name":"apparent horizon","score":0.5910000205039978},{"id":"https://openalex.org/keywords/group-delay","display_name":"group delay","score":0.5339999794960022},{"id":"https://openalex.org/keywords/gravitational-redshift","display_name":"gravitational redshift","score":0.843999981880188}],"concepts":[{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.847100019454956},{"id":"https://openalex.org/C197424946","wikidata":"https://www.wikidata.org/wiki/Q1165717","display_name":"Waveform","level":3,"score":0.6696000099182129},{"id":"https://openalex.org/C33024259","wikidata":"https://www.wikidata.org/wiki/Q76250","display_name":"Redshift","level":3,"score":0.6218000054359436},{"id":"https://openalex.org/C181500209","wikidata":"https://www.wikidata.org/wiki/Q215328","display_name":"Excited state","level":2,"score":0.569100022315979},{"id":"https://openalex.org/C50341732","wikidata":"https://www.wikidata.org/wiki/Q880302","display_name":"Black hole (networking)","level":5,"score":0.46560001373291016},{"id":"https://openalex.org/C14036430","wikidata":"https://www.wikidata.org/wiki/Q3736076","display_name":"Function (biology)","level":2,"score":0.46149998903274536},{"id":"https://openalex.org/C159176650","wikidata":"https://www.wikidata.org/wiki/Q43261","display_name":"Horizon","level":2,"score":0.3894999921321869},{"id":"https://openalex.org/C74650414","wikidata":"https://www.wikidata.org/wiki/Q11397","display_name":"Classical mechanics","level":1,"score":0.3840999901294708},{"id":"https://openalex.org/C3079626","wikidata":"https://www.wikidata.org/wiki/Q234881","display_name":"Quantum electrodynamics","level":1,"score":0.38260000944137573},{"id":"https://openalex.org/C82422596","wikidata":"https://www.wikidata.org/wiki/Q1094364","display_name":"Rotating black hole","level":3,"score":0.3562999963760376},{"id":"https://openalex.org/C106131492","wikidata":"https://www.wikidata.org/wiki/Q3072260","display_name":"Filter (signal processing)","level":2,"score":0.35190001130104065},{"id":"https://openalex.org/C196644772","wikidata":"https://www.wikidata.org/wiki/Q3884964","display_name":"Orbit (dynamics)","level":2,"score":0.3515999913215637},{"id":"https://openalex.org/C62520636","wikidata":"https://www.wikidata.org/wiki/Q944","display_name":"Quantum mechanics","level":1,"score":0.3269999921321869},{"id":"https://openalex.org/C30475298","wikidata":"https://www.wikidata.org/wiki/Q909554","display_name":"Computational physics","level":1,"score":0.3239000141620636},{"id":"https://openalex.org/C156778621","wikidata":"https://www.wikidata.org/wiki/Q1365748","display_name":"Spectrum (functional analysis)","level":2,"score":0.32109999656677246},{"id":"https://openalex.org/C140901224","wikidata":"https://www.wikidata.org/wiki/Q409415","display_name":"Airy function","level":2,"score":0.3208000063896179},{"id":"https://openalex.org/C2780870619","wikidata":"https://www.wikidata.org/wiki/Q48937708","display_name":"Quasinormal mode","level":3,"score":0.30469998717308044},{"id":"https://openalex.org/C104114177","wikidata":"https://www.wikidata.org/wiki/Q79782","display_name":"Motion (physics)","level":2,"score":0.304500013589859},{"id":"https://openalex.org/C120665830","wikidata":"https://www.wikidata.org/wiki/Q14620","display_name":"Optics","level":1,"score":0.27399998903274536},{"id":"https://openalex.org/C2775936607","wikidata":"https://www.wikidata.org/wiki/Q466845","display_name":"Tracking (education)","level":2,"score":0.26980000734329224}],"mesh":[],"locations_count":2,"locations":[{"id":"pmh:oai:arXiv.org:2609.11908","doi":null,"is_oa":true,"landing_page_url":"https://arxiv.org/abs/2609.11908","pdf_url":"https://arxiv.org/pdf/2609.11908","source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"text"},{"id":"doi:10.48550/arxiv.2609.11908","doi":"https://doi.org/10.48550/arxiv.2609.11908","is_oa":true,"landing_page_url":"https://doi.org/10.48550/arxiv.2609.11908","pdf_url":null,"source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":null,"is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"Preprint"}],"best_oa_location":{"id":"pmh:oai:arXiv.org:2609.11908","doi":null,"is_oa":true,"landing_page_url":"https://arxiv.org/abs/2609.11908","pdf_url":"https://arxiv.org/pdf/2609.11908","source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"text"},"sustainable_development_goals":[],"study_designs":[],"awards":[{"id":"https://openalex.org/G2314400263","display_name":"Fundamental Studies of Black Hole Perturbation Theory and Its Applications to Gravitational Wave Analysis","funder_award_id":"26K17142","funder_id":"https://openalex.org/F4320334764","funder_display_name":"Japan Society for the Promotion of Science"},{"id":"https://openalex.org/G6752801769","display_name":"Theoretical Study of Decoherence-Induced Quantum-to-Classical Transition of the Gravitational Field and Its Quantum Signatures","funder_award_id":"26K17146","funder_id":"https://openalex.org/F4320334764","funder_display_name":"Japan Society for the Promotion of Science"}],"funders":[{"id":"https://openalex.org/F4320334764","display_name":"Japan Society for the Promotion of Science","ror":"https://ror.org/00hhkn466"}],"has_content":{"pdf":true,"grobid_xml":true},"content_urls":{"pdf":"https://content.openalex.org/works/W7212290200.pdf","grobid_xml":"https://content.openalex.org/works/W7212290200.grobid-xml"},"referenced_works_count":33,"referenced_works":["https://openalex.org/W1984753507","https://openalex.org/W2031118610","https://openalex.org/W2031486433","https://openalex.org/W2040216147","https://openalex.org/W2046336988","https://openalex.org/W2059360084","https://openalex.org/W2147829712","https://openalex.org/W2154163781","https://openalex.org/W4405319210","https://openalex.org/W4410313913","https://openalex.org/W4414090563","https://openalex.org/W4414345406","https://openalex.org/W4414809864","https://openalex.org/W4417268244","https://openalex.org/W4417440172","https://openalex.org/W7081569764","https://openalex.org/W7139927795","https://openalex.org/W7150747379","https://openalex.org/W7163780866","https://openalex.org/W7163908685","https://openalex.org/W7163922321","https://openalex.org/W7165867153","https://openalex.org/W7166835984","https://openalex.org/W7167223556","https://openalex.org/W7167842614","https://openalex.org/W7167934651","https://openalex.org/W7172296753","https://openalex.org/W7203743272","https://openalex.org/W7204155278","https://openalex.org/W7204632545","https://openalex.org/W7212024393","https://openalex.org/W7212137845","https://openalex.org/W7213545469"],"related_works":["https://openalex.org/W7212137845","https://openalex.org/W7204155278","https://openalex.org/W7167842614","https://openalex.org/W7203743272","https://openalex.org/W7137869069","https://openalex.org/W7081569764","https://openalex.org/W7165867153","https://openalex.org/W7212024393","https://openalex.org/W7167934651","https://openalex.org/W7223067513"],"abstract_inverted_index":{"We":[0,59,79],"develop":[1,151],"a":[2,10,14,27,50,92,114,125,152],"theoretical":[3,206],"description":[4],"of":[5,52,55,64,75,91,96,124,138,197,218,222],"direct":[6],"waves":[7],"(DWs)":[8],"from":[9],"particle":[11,112,130],"plunging":[12],"into":[13,160,184],"Kerr":[15,56,189],"black":[16,57,190,230],"hole":[17],"in":[18,146],"the":[19,35,42,62,65,71,83,97,110,117,122,129,133,136,139,157,170,178,192,198,215,223],"extreme-mass-ratio":[20],"regime.":[21],"A":[22],"DW":[23,72,127],"is":[24,46,73],"characterized":[25],"by":[26,177],"source-driven":[28],"complex":[29],"frequency":[30,193],"$\u03c9_{\\rm":[31],"G}$":[32],"that":[33,61,82,109,155],"reflects":[34],"particle's":[36],"orbital":[37],"motion,":[38],"including":[39],"motion":[40],"inside":[41],"ergoregion.":[43],"Hence,":[44],"it":[45],"expected":[47],"to":[48,70],"be":[49],"probe":[51],"rich":[53],"structures":[54],"holes.":[58,231],"show":[60,81,201],"contribution":[63],"quasinormal-mode":[66],"(QNM)":[67],"pole":[68],"sector":[69],"part":[74],"dynamical":[76],"QNM":[77,179],"excitation.":[78],"also":[80],"apparent":[84],"horizon-mode":[85],"poles":[86],"cancel":[87],"at":[88],"every":[89],"order":[90],"consistent":[93],"near-horizon":[94],"expansion":[95],"trajectory,":[98],"homogeneous":[99],"radial":[100],"solution,":[101],"and":[102,119,162,186,194,225],"complete":[103],"point-particle":[104],"source.":[105],"This":[106],"result":[107],"assumes":[108],"point":[111],"follows":[113],"geodesic":[115],"near":[116,132],"horizon":[118],"leaves":[120],"open":[121],"possibility":[123,145],"transient":[126],"while":[128],"passes":[131],"ergosurface":[134],"or":[135],"vicinity":[137],"potential":[140,216],"barrier.":[141],"To":[142],"investigate":[143],"this":[144],"simulated":[147],"plunge":[148],"waveforms,":[149],"we":[150],"pole-splitting":[153],"method":[154],"decomposes":[156],"transfer":[158],"function":[159],"QNM-pole":[161],"non-pole":[163,199],"parts.":[164],"The":[165],"resulting":[166],"waveform":[167,200],"decomposition":[168],"avoids":[169],"frequency-dependent":[171],"time":[172,210],"shift":[173],"(group":[174],"delay)":[175],"introduced":[176],"filtering.":[180],"For":[181],"quasi-circular":[182],"plunges":[183],"moderately":[185],"rapidly":[187],"rotating":[188],"holes,":[191],"decay":[195],"rate":[196],"qualitative":[202],"agreement":[203],"with":[204],"our":[205],"prediction":[207],"over":[208],"finite":[209],"intervals.":[211],"These":[212],"results":[213],"support":[214],"use":[217],"DWs":[219],"as":[220],"probes":[221],"ergoregion":[224],"gravitational":[226],"redshift":[227],"effect":[228],"around":[229]},"counts_by_year":[{"year":2026,"cited_by_count":3}],"updated_date":"2026-11-08T12:12:28.789561","created_date":"2026-09-12T00:00:00"}
