We present the second data release of gravitational waveforms from binary neutron star (BNS) merger simulations performed by the Computational Relativity (
Tidal interactions in coalescing binary neutron stars modify the dynamics of the inspiral and hence imprint a signature on their gravitational wave (GW) signals in the form of an extra phase shift. We need accurate models for the tidal phase shift in order to constrain the supranuclear equation of state from observations. In previous studies, GW waveform models were typically constructed by treating the tide as a linear response to a perturbing tidal field. In this work, we incorporate nonlinear corrections due to hydrodynamic three and fourmode interactions and show how they can improve the accuracy and explanatory power of waveform models. We set up and numerically solve the coupled differential equations for the orbit and the modes and analytically derive solutions of the system’s equilibrium configuration. Our analytical solutions agree well with the numerical ones up to the merger and involve only algebraic relations, allowing for fast phase shift and waveform evaluations for different equations of state over a large parameter space. We find that, at Newtonian order, nonlinear fluid effects can enhance the tidal phase shift by $\gtrsim 1\, {\rm radian}$ at a GW frequency of 1000 Hz, corresponding to a $10{{\%}}20{{\%}}$ correction to the linear theory. The scale of the more »
 Award ID(s):
 2054353
 Publication Date:
 NSFPAR ID:
 10391236
 Journal Name:
 Monthly Notices of the Royal Astronomical Society
 Volume:
 519
 Issue:
 3
 Page Range or eLocationID:
 p. 43254343
 ISSN:
 00358711
 Publisher:
 Oxford University Press
 Sponsoring Org:
 National Science Foundation
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