4 research outputs found
Inspiral-merger-ringdown waveforms of spinning, precessing black-hole binaries in the effective-one-body formalism
We describe a general procedure to generate spinning, precessing waveforms
that include inspiral, merger and ringdown stages in the effective-one-body
(EOB) approach. The procedure uses a precessing frame in which
precession-induced amplitude and phase modulations are minimized, and an
inertial frame, aligned with the spin of the final black hole, in which we
carry out the matching of the inspiral-plunge to merger-ringdown waveforms. As
a first application, we build spinning, precessing EOB waveforms for the
gravitational modes l=2 such that in the nonprecessing limit those waveforms
agree with the EOB waveforms recently calibrated to numerical-relativity
waveforms. Without recalibrating the EOB model, we then compare EOB and
post-Newtonian precessing waveforms to two numerical-relativity waveforms
produced by the Caltech-Cornell-CITA collaboration. The numerical waveforms are
strongly precessing and have 35 and 65 gravitational-wave cycles. We find a
remarkable agreement between EOB and numerical-relativity precessing waveforms
and spins' evolutions. The phase difference is ~ 0.2 rad at merger, while the
mismatches, computed using the advanced-LIGO noise spectral density, are below
2% when maximizing only on the time and phase at coalescence and on the
polarization angle.Comment: 17 pages, 10 figure
Suitability of hybrid gravitational waveforms for unequal-mass binaries
This article studies sufficient accuracy criteria of hybrid post-Newtonian
(PN) and numerical relativity (NR) waveforms for parameter estimation of strong
binary black-hole sources in second- generation ground-based gravitational-wave
detectors. We investigate equal-mass non-spinning binaries with a new 33-orbit
NR waveform, as well as unequal-mass binaries with mass ratios 2, 3, 4 and 6.
For equal masses, the 33-orbit NR waveform allows us to recover previous
results and to extend the analysis toward matching at lower frequencies. For
unequal masses, the errors between different PN approximants increase with mass
ratio. Thus, at 3.5PN, hybrids for higher-mass-ratio systems would require NR
waveforms with many more gravitational-wave (GW) cycles to guarantee no adverse
impact on parameter estimation. Furthermore, we investigate the potential
improvement in hybrid waveforms that can be expected from 4th order
post-Newtonian waveforms, and find that knowledge of this 4th post-Newtonian
order would significantly improve the accuracy of hybrid waveforms.Comment: 11 pages, 14 figure
Discontinuous Galerkin method for the spherically reduced BSSN system with second-order operators
We present a high-order accurate discontinuous Galerkin method for evolving
the spherically-reduced Baumgarte-Shapiro-Shibata-Nakamura (BSSN) system
expressed in terms of second-order spatial operators. Our multi-domain method
achieves global spectral accuracy and long-time stability on short
computational domains. We discuss in detail both our scheme for the BSSN system
and its implementation. After a theoretical and computational verification of
the proposed scheme, we conclude with a brief discussion of issues likely to
arise when one considers the full BSSN system.Comment: 35 pages, 6 figures, 1 table, uses revtex4. Revised in response to
referee's repor