Quadrupole and quadratic-in-spin effects in quasicircular, spinning, asymmetric binaries
Abstract
Next-generation gravitational-wave detectors will require significant improvements in current theoretical waveform models, particularly in the case of asymmetric-mass binaries. Here we provide one such improvement by calculating fully relativistic finite-size effects for small mass ratios -- primarily, fluxes of energy -- including quadratic-in-secondary-spin terms, spin-induced quadrupole terms, and tidally induced quadrupole terms, for quasicircular inspirals of a small companion into a Kerr black hole. We formulate these calculations within a multiscale waveform-generation framework in self-force theory, which could be used, with an energy-balance law we derive, to develop self-contained waveform models for asymmetric binaries involving stars orbiting black holes. Our results could additionally be used to improve other families of waveform models across all mass ratios. We present results both as complete numerical data sets on a Chebyshev grid and as analytical post-Newtonian expansions (to sixth PN order relative to the leading term in each contribution to the flux).
Versions
Related
- Second-order Teukolsky calculations for nonspinning, quasicircular binaries
- Dynamics of spinning test particles in the innermost stable circular orbit of an approximate Kerr-like spacetime with mass quadrupole
- Evolution dynamics of spinning binaries in effective-one-body theory to fifth Post-Minkowskian order
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BibTeX
@misc{rahman2026quadrupole,
title = {{Quadrupole and quadratic-in-spin effects in quasicircular, spinning, asymmetric binaries}},
author = {Mostafizur Rahman and Misbah Shahzadi and Adam Pound and Josh Mathews},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2606.28937},
eprint = {2606.28937},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.28937},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Quadrupole and quadratic-in-spin effects in quasicircular, spinning, asymmetric binaries
AU - Mostafizur Rahman
AU - Misbah Shahzadi
AU - Adam Pound
AU - Josh Mathews
PY - 2026
DA - 2026/10/15
PB - arXiv
DO - 10.48550/arxiv.2606.28937
UR - https://arxiv.org/abs/2606.28937
AB - Next-generation gravitational-wave detectors will require significant improvements in current theoretical waveform models, particularly in the case of asymmetric-mass binaries. Here we provide one such improvement by calculating fully relativistic finite-size effects for small mass ratios -- primarily, fluxes of energy -- including quadratic-in-secondary-spin terms, spin-induced quadrupole terms, and tidally induced quadrupole terms, for quasicircular inspirals of a small companion into a Kerr black hole. We formulate these calculations within a multiscale waveform-generation framework in self-force theory, which could be used, with an energy-balance law we derive, to develop self-contained waveform models for asymmetric binaries involving stars orbiting black holes. Our results could additionally be used to improve other families of waveform models across all mass ratios. We present results both as complete numerical data sets on a Chebyshev grid and as analytical post-Newtonian expansions (to sixth PN order relative to the leading term in each contribution to the flux).
ER -