Surrogate model for gravitational wave signals from non-spinning, comparable- to large-mass-ratio black hole binaries built on black hole perturbation theory waveforms calibrated to numerical relativity

TL;DR

This paper introduces a surrogate model for gravitational waveforms from non-spinning black hole binaries with a wide range of mass ratios, calibrated to numerical relativity data, enhancing waveform accuracy and coverage.

Contribution

The authors develop HPTNRSur1dq1e4, a new surrogate model trained on perturbation theory waveforms, extended to include more modes and calibrated to NR data, covering mass ratios from 2.5 to 10,000.

Findings

Waveforms agree with NR data within 10^{-3} for dominant modes.

Model covers longer durations up to 30,500 m_1.

Includes multiple spherical harmonic modes up to ll=10.

Abstract

We present a reduced-order surrogate model of gravitational waveforms from non-spinning binary black hole systems with comparable to large mass-ratio configurations. This surrogate model, \texttt{BHPTNRSur1dq1e4}, is trained on waveform data generated by point-particle black hole perturbation theory (ppBHPT) with mass ratios varying from 2.5 to 10,000. \texttt{BHPTNRSur1dq1e4} extends an earlier waveform model, \texttt{EMRISur1dq1e4}, by using an updated transition-to-plunge model, covering longer durations up to 30,500 $m_1$ (where $m_1$ is the mass of the primary black hole), includes several more spherical harmonic modes up to $\ell=10$, and calibrates subdominant modes to numerical relativity (NR) data. In the comparable mass-ratio regime, including mass ratios as low as $2.5$, the gravitational waveforms generated through ppBHPT agree surprisingly well with those from NR after this simple calibration step. We also compare our model to recent SXS and RIT NR simulations at mass ratios ranging from $15$ to $32$, and find the dominant quadrupolar modes agree to better than $\approx 10^{-3}$. We expect our model to be useful to study intermediate-mass-ratio binary systems in current and future gravitational-wave detectors.