Pipeline to search for signatures of line-of-sight acceleration in gravitational wave signals produced by compact binary coalescences
Phys. Rev. D 113, 104072 – Published 29 May, 2026
DOI: https://doi.org/10.1103/qtw8-3g56
Abstract
Compact binary coalescences (CBCs), such as merging binary black holes (BBHs), binary neutron stars (BNSs), or neutron star black holes (NSBHs), hosted by dense stellar environments, could produce gravitational waves (GWs) that contain signatures of line-of-sight acceleration (LOSA) imparted by the environment’s gravitational potential. We calculate the post-Newtonian (PN) corrections to the (2,2) mode GW phase due to a finite LOSA, starting from the leading order at –4 PN below the quadrupole order, up to 3.5PN above the leading order correction. We do so for binaries whose component spins are aligned with the orbital angular momentum, as well as for binaries with nonzero tidal deformation. We implement these corrections into the LIGO-Virgo-Kagra (LVK) collaboration’s flagship parameter estimation (PE) software bilby_tgr. We study the systematics associated with recovering LOSAs. We find that, when the injection and recovery waveform models are identical, LOSAs are recovered as expected. We test the robustness of the pipeline against waveforms with strong higher-mode signatures or signatures of beyond-general-relativistic (beyond-GR) effects to delimit the range of applicability of our GR-consistent quasicircular LOSA-corrected waveforms.
