Surrogate model for an alignedspin effectiveonebody waveform model of binary neutron star inspirals using Gaussian process regression
Abstract
Fast and accurate waveform models are necessary for measuring the properties of inspiraling binary neutron star systems such as GW170817. We present a frequencydomain surrogate version of the alignedspin binary neutron star waveform model using the effectiveonebody formalism known as SEOBNRv4T. This model includes the quadrupolar and octopolar adiabatic and dynamical tides. The version presented here is improved by the inclusion of the spininduced quadrupole moment effect and completed by a prescription for tapering the end of the waveform to qualitatively reproduce numerical relativity simulations. The resulting model has 14 intrinsic parameters. We reduce its dimensionality by using universal relations that approximate all matter effects in terms of the leading quadrupolar tidal parameters. The implementation of the timedomain model can take up to an hour to evaluate using a starting frequency of 20 Hz, and this is too slow for many parameter estimation codes that require O (10^{7}) sequential waveform evaluations. We therefore construct a fast and faithful frequencydomain surrogate of this model using Gaussian process regression. The resulting surrogate has a maximum mismatch of 4.5 ×10^{4} for the Advanced LIGO detector and requires ∼0.13 s to evaluate for a waveform with a starting frequency of 20 Hz. Finally, we perform an endtoend test of the surrogate with a set of parameter estimation runs and find that the surrogate accurately recovers the parameters of injected waveforms.
 Publication:

Physical Review D
 Pub Date:
 July 2019
 DOI:
 10.1103/PhysRevD.100.024002
 arXiv:
 arXiv:1812.08643
 Bibcode:
 2019PhRvD.100b4002L
 Keywords:

 General Relativity and Quantum Cosmology
 EPrint:
 19 pages, 10 figures, submitted to PRD