Psaltis, DimitriosDimitriosPsaltisMedeiros, LiaLiaMedeirosChristian, PierrePierreChristianÖzel, FeryalFeryalÖzelAkiyama, KazunoriKazunoriAkiyamaAlberdi, AntxonAntxonAlberdiAlef, WalterWalterAlefAsada, KeiichiKeiichiAsadaAzulay, RebeccaRebeccaAzulayBall, DavidDavidBallBaloković, MislavMislavBalokovićBarrett, JohnJohnBarrettBintley, DanDanBintleyBlackburn, LindyLindyBlackburnBoland, WilfredWilfredBolandBower, Geoffrey C.Geoffrey C.BowerBremer, MichaelMichaelBremerBrinkerink, Christiaan D.Christiaan D.BrinkerinkBrissenden, RogerRogerBrissendenBritzen, SilkeSilkeBritzenBroguiere, DominiqueDominiqueBroguiereBronzwaer, ThomasThomasBronzwaerByun, Do-YoungDo-YoungByunCarlstrom, John E.John E.CarlstromChael, AndrewAndrewChaelChan, Chi-kwanChi-kwanChanChatterjee, ShamiShamiChatterjeeChatterjee, KoushikKoushikChatterjeeChen, Ming-TangMing-TangChenChen, YongjunYongjunChenCho, IljeIljeChoConway, John E.John E.ConwayCordes, James M.James M.CordesCrew, Geoffrey B.Geoffrey B.CrewCui, YuzhuYuzhuCuiDavelaar, JordyJordyDavelaarDe Laurentis, MariafeliciaMariafeliciaDe LaurentisDeane, RogerRogerDeaneDempsey, JessicaJessicaDempseyDesvignes, GregoryGregoryDesvignesDexter, JasonJasonDexterEatough, Ralph P.Ralph P.EatoughFalcke, HeinoHeinoFalckeFish, Vincent L.Vincent L.FishFomalont, EdEdFomalontFraga-Encinas, RaquelRaquelFraga-EncinasFriberg, PerPerFribergFromm, Christian M.Christian M.FrommGammie, Charles F.Charles F.GammieGarcía, RobertoRobertoGarcíaGentaz, OlivierOlivierGentazGoddi, CiriacoCiriacoGoddiGómez, José L.José L.GómezGu, MinfengMinfengGuGurwell, MarkMarkGurwellHada, KazuhiroKazuhiroHadaHesper, RonaldRonaldHesperHo, Luis C.Luis C.HoHo, PaulPaulHoHonma, MarekiMarekiHonmaHuang, Chih-Wei L.Chih-Wei L.HuangHuang, LeiLeiHuangHughes, David H.David H.HughesInoue, MakotoMakotoInoueIssaoun, SaraSaraIssaounJames, David J.David J.JamesJannuzi, Buell T.Buell T.JannuziJanssen, MichaelMichaelJanssenJiang, WuWuJiangJimenez-Rosales, AlejandraAlejandraJimenez-RosalesJohnson, Michael D.Michael D.JohnsonJorstad, SvetlanaSvetlanaJorstadJung, TaehyunTaehyunJungKarami, MansourMansourKaramiKaruppusamy, RameshRameshKaruppusamyKawashima, TomohisaTomohisaKawashimaKeating, Garrett K.Garrett K.KeatingKettenis, MarkMarkKettenisKim, Jae-YoungJae-YoungKimKim, JunhanJunhanKimKim, JongsooJongsooKimKino, MotokiMotokiKinoKoay, Jun YiJun YiKoayKoch, Patrick M.Patrick M.KochKoyama, ShokoShokoKoyamaKramer, MichaelMichaelKramerKramer, CarstenCarstenKramerKrichbaum, Thomas P.Thomas P.KrichbaumKuo, Cheng-YuCheng-YuKuoLauer, Tod R.Tod R.LauerLee, Sang-SungSang-SungLeeLi, Yan-RongYan-RongLiLi, ZhiyuanZhiyuanLiLindqvist, MichaelMichaelLindqvistLICO, RoccoRoccoLICOLiu, JunJunLiuLiu, KuoKuoLiuLIUZZO, Elisabetta TeodorinaElisabetta TeodorinaLIUZZOLo, Wen-PingWen-PingLoLobanov, Andrei P.Andrei P.LobanovLonsdale, ColinColinLonsdaleLu, Ru-SenRu-SenLuMao, JirongJirongMaoMarkoff, SeraSeraMarkoffMarrone, Daniel P.Daniel P.MarroneMarscher, Alan P.Alan P.MarscherMartí-Vidal, IvánIvánMartí-VidalMatsushita, SatokiSatokiMatsushitaMizuno, YosukeYosukeMizunoMizuno, IzumiIzumiMizunoMoran, James M.James M.MoranMoriyama, KotaroKotaroMoriyamaMoscibrodzka, MonikaMonikaMoscibrodzkaMüller, CorneliaCorneliaMüllerMusoke, GibwaGibwaMusokeMus Mejías, AlejandroAlejandroMus MejíasNagai, HiroshiHiroshiNagaiNagar, Neil M.Neil M.NagarNarayan, RameshRameshNarayanNarayanan, GopalGopalNarayananNatarajan, IniyanIniyanNatarajanNeri, RobertoRobertoNeriNoutsos, AristeidisAristeidisNoutsosOkino, HirokiHirokiOkinoOlivares, HéctorHéctorOlivaresOyama, TomoakiTomoakiOyamaPalumbo, Daniel C. M.Daniel C. M.PalumboPark, JonghoJonghoParkPatel, NimeshNimeshPatelPen, Ue-LiUe-LiPenPiétu, VincentVincentPiétuPlambeck, RichardRichardPlambeckPopStefanija, AleksandarAleksandarPopStefanijaPrather, BenBenPratherPreciado-López, Jorge A.Jorge A.Preciado-LópezRamakrishnan, VenkatesshVenkatesshRamakrishnanRao, RamprasadRamprasadRaoRawlings, Mark G.Mark G.RawlingsRaymond, Alexander W.Alexander W.RaymondRipperda, BartBartRipperdaRoelofs, FreekFreekRoelofsRogers, AlanAlanRogersRos, EduardoEduardoRosRose, MelMelRoseRoshanineshat, ArashArashRoshanineshatRottmann, HelgeHelgeRottmannRoy, Alan L.Alan L.RoyRuszczyk, ChetChetRuszczykRyan, Benjamin R.Benjamin R.RyanRYGL, Kazi Lucie JessicaKazi Lucie JessicaRYGLSánchez, SalvadorSalvadorSánchezSánchez-Arguelles, DavidDavidSánchez-ArguellesSasada, MahitoMahitoSasadaSavolainen, TuomasTuomasSavolainenSchloerb, F. PeterF. PeterSchloerbSchuster, Karl-FriedrichKarl-FriedrichSchusterShao, LijingLijingShaoShen, ZhiqiangZhiqiangShenSmall, DesDesSmallSohn, Bong WonBong WonSohnSooHoo, JasonJasonSooHooTazaki, FumieFumieTazakiTilanus, Remo P. J.Remo P. J.TilanusTitus, MichaelMichaelTitusTorne, PabloPabloTorneTrent, TylerTylerTrentTraianou, EfthaliaEfthaliaTraianouTrippe, SaschaSaschaTrippevan Bemmel, IlseIlsevan Bemmelvan Langevelde, Huib JanHuib Janvan Langeveldevan Rossum, Daniel R.Daniel R.van RossumWagner, JanJanWagnerWardle, JohnJohnWardleWard-Thompson, DerekDerekWard-ThompsonWeintroub, JonathanJonathanWeintroubWex, NorbertNorbertWexWharton, RobertRobertWhartonWielgus, MaciekMaciekWielgusWong, George N.George N.WongWu, QingwenQingwenWuYoon, DoosooDoosooYoonYoung, AndréAndréYoungYoung, KenKenYoungYounsi, ZiriZiriYounsiYuan, FengFengYuanYuan, Ye-FeiYe-FeiYuanZhao, Shan-ShanShan-ShanZhaoEHT Collaboration2025-03-102025-03-1020200031-9007http://hdl.handle.net/20.500.12386/36618The 2017 Event Horizon Telescope (EHT) observations of the central source in M87 have led to the first measurement of the size of a black-hole shadow. This observation offers a new and clean gravitational test of the black-hole metric in the strong-field regime. We show analytically that spacetimes that deviate from the Kerr metric but satisfy weak-field tests can lead to large deviations in the predicted black-hole shadows that are inconsistent with even the current EHT measurements. We use numerical calculations of regular, parametric, non-Kerr metrics to identify the common characteristic among these different parametrizations that control the predicted shadow size. We show that the shadow-size measurements place significant constraints on deviation parameters that control the second post-Newtonian and higher orders of each metric and are, therefore, inaccessible to weak-field tests. The new constraints are complementary to those imposed by observations of gravitational waves from stellar-mass sources.STAMPAenArticle10.1103/PhysRevLett.125.1411042-s2.0-85093357361https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.141104http://arxiv.org/abs/2010.01055v12020PhRvL.125n1104PFIS/05 - ASTRONOMIA E ASTROFISICA