English

Adding higher-order spherical harmonics in non-spinning eccentric binary black hole merger waveform models

General Relativity and Quantum Cosmology 2025-09-16 v1

Abstract

gwNRHME is a recently developed framework that seamlessly converts a multi-modal (i.e with several spherical harmonic modes) quasi-circular waveform into multi-modal eccentric waveform if the quadrupolar eccentric waveform is known. Here, we employ the gwNRHME framework to combine a multi-modal quasi-circular waveform model NRHybSur3dq8 and quadrupolar non-spinning eccentric waveform model EccentricIMR to construct multi-modal non-spinning eccentric model NRHybSur3dq8-gwNRHME. Using a total of 35 eccentric numerical relativity (NR) simulations obtained from the SXS and RIT catalogs, we demonstrate that NRHybSur3dq8-gwNRHME model predictions agree well with NR (with typical relative L2L_2 errors of ~0.01 for the dominant quadrupolar mode) for mass ratios 1q4 1 \leq q \leq 4 and eccentricities up to ~0.2 measured about 10 cycles before the merger. To demonstrate the modularity of the gwNRHME framework, we further combine EccentricIMR with BHPTNRSur1dq1e4 model and develop a non-spinning eccentric models named BHPTNRSur1dq1e4-gwNRHME. Finally, we develop a different variant of these models by replacing EccentricIMR with EccentricTD. Both the gwNRHME framework and associated models are available through the gwModels package.

Keywords

Cite

@article{arxiv.2408.02762,
  title  = {Adding higher-order spherical harmonics in non-spinning eccentric binary black hole merger waveform models},
  author = {Tousif Islam and Gaurav Khanna and Scott E. Field},
  journal= {arXiv preprint arXiv:2408.02762},
  year   = {2025}
}

Comments

14 pages, 11 figures

R2 v1 2026-06-28T18:04:42.120Z