Effective-one-body model for black-hole binaries with generic mass ratios and spins

Abstract

Gravitational waves emitted by black-hole binary systems have the highest signal-to-noise ratio in LIGO and Virgo detectors when black-hole spins are aligned with the orbital angular momentum and extremal. For such systems, we extend the effective-one-body inspiral-merger-ringdown waveforms to generic mass ratios and spins calibrating them to 38 numerical-relativity nonprecessing waveforms produced by the SXS Collaboration. The numerical-relativity simulations span mass ratios from 1 to 8, spin magnitudes up to 98% of extremality, and last for 40 to 60 gravitational-wave cycles. When the total mass of the binary is between 20 and 200M ⊙ , the effective-one-body nonprecessing (dominant mode) waveforms have overlap above 99% (using the advanced-LIGO design noise spectral density) with all of the 38 nonprecessing numerical waveforms, when maximizing only on initial phase and time. This implies a negligible loss in event rate due to modeling. We also show that-without further calibration-the precessing effective-onebody (dominant mode) waveforms have overlap above 97% with two very long, strongly precessing numerical-relativity waveforms, when maximizing only on the initial phase and time.

Reconstructing the sky location of gravitational-wave detected compact binary systems: Methodology for testing and comparison

“…Our likelihood model, pðdjθ; HÞ, could be incorrect because of inaccuracies in the waveform models, noise models or calibration errors. Waveforms may not include certain features (e.g., in this study, we did not allow for spinning binary components) or are affected by limitations in the accuracy of waveform models; efforts are under way to develop more accurate and complete models [36,37] and to account for waveform uncertainty directly in parameter estimation. Real detector noise is neither stationary nor Gaussian; promising strides have been made in accounting for noise nonstationarity [38], shifts in spectral lines and even glitches in the noise.…”

Sources of Gravitational Waves: Theory and Observations

“…EOB waveforms are also stable with respect to the length of the numerical waveforms [344]. EOB waveforms for non-precessing systems with any mass ratio and spin have also been developed and calibrated to existing, highly accurate numerical waveforms, which, however, do not yet span the overall parameter space [354]. EOB waveforms for precessing systems can be built from those for non-precessing ones [356]; they capture remarkably well the spin-induced modulations in the long inspiral of NR waveforms and will be calibrated and improved in the near future.…”

“…As a consequence, higher-order PN terms (in particular, the test-particle limit terms) are included in the gravitational modes h m [277,292,346]. Since PN corrections are not yet fully known in the twobody dynamics, higher-order PN terms are included in the EOB dynamics with arbitrary coefficients [302,[346][347][348][349][350][351][352][353][354], which are then calibrated by minimising the phase and amplitude difference between EOB and NR waveforms aligned at low frequency. Those coefficients have been denoted adjustable or flexible parameters.…”

Approaching the Post-Newtonian Regime with Numerical Relativity: A Compact-Object Binary Simulation Spanning 350 Gravitational-Wave Cycles

“…This gap has emerged as one of the most important sources of uncertainty in present IMR waveform models. It is possible to construct IMR models by extending analytical waveforms across the gap [20][21][22][23], in some cases, obtaining IMR models that are faithful to longer numerical waveforms when extrapolated beyond their limited range of calibration [30]. However, so far these procedures have been tested using NR simulations with only 30 orbits, too few to close the gap.…”

“…(Besides its importance for GW astronomy, NR has also deepened the understanding of general relativity in topics such as binary BH recoil [15,16], gravitational self-force [17], highenergy physics, and cosmology [18,19].) Current inspiral-merger-ringdown (IMR) waveform models [20][21][22][23] combine information from analytical-relativity (AR) calculations (best suited for the inspiral, when comparablemass binaries have characteristic velocities smaller than the speed of light) and direct NR simulations (the best means to explore the late inspiral and the merger).…”