Frequency domain reduced order model of aligned-spin effective-one-body waveforms with generic mass-ratios and spins

TL;DR

This paper develops a frequency domain reduced order model for the SEOBNRv2 gravitational wave waveform, enabling efficient data analysis for black hole binary signals across a broad parameter space with high accuracy.

Contribution

The paper introduces a new ROM for SEOBNRv2 that handles a large parameter space with improved resolution and accuracy, facilitating faster GW data analysis.

Findings

ROM achieves mismatches better than 0.1% against SEOBNRv2.

ROM is applicable for total masses above 2 solar masses with aLIGO sensitivity.

Discontinuities in waveform connection increase resolution needs in certain parameter regions.

Abstract

I provide a frequency domain reduced order model (ROM) for the aligned-spin effective-one-body (EOB) model "SEOBNRv2" for data analysis with second and third generation ground based gravitational wave (GW) detectors. SEOBNRv2 models the dominant mode of the GWs emitted by the coalescence of black hole (BH) binaries. The large physical parameter space (dimensionless spins $-1 \leq \chi_i \leq 0.99$ and symmetric mass-ratios $0.01 \leq \eta \leq 0.25$) requires sophisticated reduced order modeling techniques, including patching in the parameter space and in frequency. I find that the time window over which the inspiral-plunge and the merger-ringdown waveform in SEOBNRv2 are connected is discontinuous when the spin of the deformed Kerr BH $\chi=0.8$ or the symmetric mass-ratio $\eta \sim 0.083$. This discontinuity increases resolution requirements for the ROM. The ROM can be used for compact binary systems with total masses of $2 M_\odot$ or higher for the advanced LIGO (aLIGO) design sensitivity and a $10$ Hz lower cutoff frequency. The ROM has a worst mismatch against SEOBNRv2 of $\sim 1\%$, but in general mismatches are better than $\sim 0.1\%$. The ROM is crucial for key data analysis applications for compact binaries, such as GW searches and parameter estimation carried out within the LIGO Scientific Collaboration (LSC).