LIGO-Virgo data analysis Archisman Ghosh Nikhef, Amsterdam 7 th - PowerPoint PPT Presentation

. LIGO-Virgo data analysis Archisman Ghosh Nikhef, Amsterdam 7 th Belgian-Dutch Gravitational Waves Meeting Van Swinderen Institute for Particle Physics and Gravity, University of Groningen 2018 May 29

. Plan of talk Orientation and basics of GW data analysis Searches − → parameter estimation − → science implications Testing general relativity Results with O1 and O2 detections Future prospects in afternoon session Cosmology GW170817 result Future prospects in afternoon session Neutron star equation-of-state; astrophysics Talks by Tania Hinderer and Tim Dietrich contribution and efforts in NL 2 of 16

. Gravitational-wave sources Weak Strong Unmodelled Stochastic Bursts background Cosmological + BBH Supernova explosions Modelled Compact binary Continuous waves coalescences Spinning deformed NS NS-NS, NS-BH, BBH 3 of 16

. Data analysis of CBCs Searches Parameter estimation Implications Generate (real-time) triggers Rigorous analysis of data around trigger Fundamental physics, astrophysics, cosmology Abbott et al. , PRX 6 , 041015 (2016) Low latency High latency quick accurate BayesSTAR LALInference RapidPE 4 of 16

. Searches MATCHED FILTERING COINCIDENT TRIGGER Abbott et al. , PRX 6 , 041015 (2016) BACKGROUND RANKING & SIGNIFICANCE TEMPLATE BANK For further details: Sarah Caudill 5 of 16

. Parameter estimation Intrinsic parameters: { m 1 , m 2 ,� s 2 , λ 1 , λ 2 , . . . } s 1 ,� Extrinsic parameters: { α, δ, d L , ι, ψ, φ c , t c } At least 15 parameters for BBHs At least 17 parameters for BNS Bayesian parameter estimation: obtain the posterior probability distribution on the parameter space given the data and a prior probability distribution. Ω | data , I ) = Prior ( � Ω | I ) L (data | � Ω , I ) Posterior ( � Evidence (data , I ) LALInference : to perform a stochastic sampling of the posterior probability distribution over parameter space. Veitch & Vecchio (2009); Veitch et al. (2014) 6 of 16

. Abbott et al. , PRL 116 , 061102 (2016) Parameter estimation results GW150914 40 35 30 secondary mass (M ⊙ ) GW150914 25 GW170814 20 GW170104 15 10 LVT151012 GW151226 5 GW170608 LIGO/Virgo/Patricia Schmidt 0 10 20 30 40 50 60 primary mass (M ⊙ ) GW170104 LVT151012 GW170608 GW151226 GW170817 GW150914 GW170814 LIGO/Virgo/NASA/Leo Singer (Milky Way image: Axel Mellinger) GW170817 7 of 16 Abbott et al. , PRL 119 , 161101 (2017)

. Abbott et al. , PRL 116 , 061102 (2016) Testing general relativity First probes into the dynamical regime of strong field general relativity (GR). Yunes et al. (2016) -2 10 GW151226 -3 10 -4 10 GW150914 -1 ] -5 10 1/2 [km -6 10 -7 10 3 ) LAGEOS -8 Double Binary Pulsar 1/2 =(M/L 10 -9 10 -10 10 Abbott et al. , PRL 116 , 221101 (2016) Lunar Laser Ranging R -11 Pulsar Timing Arrays 10 -12 10 Perihelion Precession of Mercury -13 10 -14 10 -4 10 0 10 4 10 8 10 12 10 16 10 20 10 24 10 28 10 32 10 36 10 40 10 44 10 48 10 8 of 16 |T|=|E b / . E b | [s]

. Inspiral-merger-ringdown consistency test Mass and spin of the remnant object estimated from the inspiral and merger-ringdown parts agree with each other given GR predictions. Ghosh et al. (2016); Ghosh et al. (2017) GW150914 Might not have been true in modified GR. Abbott et al. , PRL 116 , 221101 (2016) Abbott et al. , PRL 118 , 221101 (2017) GW150914 + GW170104 Stronger constraints on systematic departures from GR combining information from multiple detections. 9 of 16

. Constraints on parameterized deformations from GR � v � 0 � v � 1 � v � 2 � v � 3 � v � 4 � v � 5 � v � 6 � v � 7 c c c c c c c c Allowing coefficients in waveform models to deviate from their GR values, the deviation parameters do not show any departure from their GR values. Li et al. (2011); Agathos et al. (2013); Meidam (PhD thesis, 2017); Meidam et al. (2017) GW150914 + GW151226 + GW170104 GW150914 Abbott et al. , PRL 116 , 221101 (2016) Abbott et al. , PRL 118 , 221101 (2017) → First-ever measurement of orbital dynamics − beyond leading order in v / c . − − − � 3 coefficient constrained to O (10%) � v Deviation in c Dynamical self-interaction of spacetime Spin-orbit interaction 10 of 16

. Constraints from modified dispersion Will (1998); Mirshekari et al. (2012) Modified dispersion relation: (different frequencies travel with different speeds) E 2 = p 2 c 2 + A p α c α λ A ≡ hc A 1 / ( α − 2) α � = 0 → local Lorentz invariance violation GW150914 + GW151226 + GW170104 α = 0 → massive graviton Abbott et al. , PRL 118 , 221101 (2017) GW150914 + GW151226 + GW170104 h GW170104 m g c > 1 . 6 × 10 13 km λ g ≡ m g < 7 . 7 × 10 − 23 eV / c 2 Effect gets enhanced with propagation over a distance! Hubble scale ≈ 1 . 3 × 10 23 km Agathos (PhD thesis, 2016); Samajdar (PhD thesis, 2017); Samajdar & Arun (2017) 11 of 16

. Polarization from 3-detector observation of GW170814 six polarizations − → distinct antenna patterns In GR: GW are transverse, traceless only tensor polarizations pure tensor / pure scalar = 1000 / 1 pure tensor / pure vector = 200 / 1 Isi & Weinstein (2017) Need multiple detectors: thanks to Virgo! Abbott et al. , PRL 119 , 141101 (2017) 12 of 16

. Constraints from GW170817+GRB Delay of only a few seconds after a propa- gation over one hundred million light years. t EM − t GW = 1 . 74 ± 0 . 05 s Constraints on speed of gravity assuming GRB emitted within 10s of GW − 3 × 10 − 15 � v GW − v EM � +7 × 10 − 16 v EM “Shapiro time delay” of GW and EM in the gravitational potential of our galaxy: − 2 . 6 × 10 − 7 � γ GW − γ EM � 1 . 2 × 10 − 6 Test of the equivalence principle. Abbott et al. Astrophys. J. 848 #2, L13 (2017) 13 of 16

. Probing the nature of the progenitor and remnant compact objects Are they really black holes, or exotic compact objects mimicking black holes? Boson stars, dark matter stars, gravastars, shells, wormholes Three “complementary” ways in three different regimes: ♣ Anomalous tidal effects during inspiral. ♣ No-hair theorem with quasinormal modes. Talk by Anuradha Samajdar ♣ Search for post-merger oscillations or “echoes”. Talk by Ka Wa Tsang 14 of 16

. Cosmology: Hubble parameter with GW170817 observed v recession = vH + v peculiar universe is not homogeneous at small scales: galaxies attracted towards local matter overdensities NGC 4993: v recession = 3327 ± 72 km s − 1 Correct for peculiar velocity of group of galaxies vH = 3017 ± 166 km s − 1 Optical counterpart: SSS17a Host galaxy: NGC 4993 Distance, dL = 43 . 8+2 . 9 − 6 . 9Mpc (assuming sky location of counterpart) H 0 = 70 . 0 +12 . 0 − 8 . 0 km s − 1 Mpc − 1 Independent of any distance ladder! Abbott et al. Astrophys. J. 848 #2, L12 (2017); LSC-EPO Abbott et al. Nature 551 #7678, 85-88 (2017) 15 of 16 More details and future prospects in talk by Ankan Sur

. Summary and outlook A multitude of detections! Consistency with GR of LIGO-Virgo detections: Consistency of the waveform model. Constraints on parameterized deformations from GR. Bound on mass of graviton and on violation of local Lorentz invariance. Evidence against alternate polarizations with a 3-detector network. Measurement of speed of gravity and a test of the equivalence principle. Cosmology: Measurement of Hubble parameter independent of cosmic distance ladder. The future of science with gravitational waves is promising! 16 of 16