Numerical-relativity surrogate models for both black-hole merger waveforms and remnants have emerged as important tools in gravitational-wave astronomy. While producing very accurate predictions, their applicability is limited to the region of the parameter space where numerical-relativity simulations are available and computationally feasible. Notably, this excludes extreme mass ratios. We present a machine-learning approach to extend the validity of existing and future numerical-relativity surrogate models toward the test-particle limit, targeting in particular the mass and spin of post-merger black-hole remnants. Our model is trained on both numerical-relativity simulations at comparable masses and analytical predictions at extreme mass ratios. We extend the gaussian-process-regression model NRSur7dq4Remnant, validate its performance via cross validation, and test its accuracy against additional numerical-relativity runs. Our fit, which we dub NRSur7dq4EmriRemnant, reaches an accuracy that is comparable to or higher than that of existing remnant models while providing robust predictions for arbitrary mass ratios.
@article{arxiv.2307.03435,
title = {Extending black-hole remnant surrogate models to extreme mass ratios},
author = {Matteo Boschini and Davide Gerosa and Vijay Varma and Cristobal Armaza and Michael Boyle and Marceline S. Bonilla and Andrea Ceja and Yitian Chen and Nils Deppe and Matthew Giesler and Lawrence E. Kidder and Prayush Kumar and Guillermo Lara and Oliver Long and Sizheng Ma and Keefe Mitman and Peter James Nee and Harald P. Pfeiffer and Antoni Ramos-Buades and Mark A. Scheel and Nils L. Vu and Jooheon Yoo},
journal= {arXiv preprint arXiv:2307.03435},
year = {2023}
}
Comments
10 pages, 3 figures. Published in PRD. Model publicly available at https://pypi.org/project/surfinBH