Post-Newtonian inspiral waveform model for eccentric precessing binaries with higher-order modes and matter effects

TL;DR

pyEFPEHM is an advanced post-Newtonian waveform model for eccentric, precessing binaries that incorporates higher-order modes and matter effects, improving accuracy and efficiency for gravitational-wave analysis.

Contribution

It extends previous models by including higher PN order corrections, eccentricity effects, and spin precession, offering a more comprehensive and accurate inspiral waveform model.

Findings

Validates pyEFPEHM against analytical and numerical relativity waveforms.

Shows good agreement across broad parameter space up to near merger.

Accuracy decreases for systems with high mass ratio, high spins, or high eccentricity.

Abstract

We introduce pyEFPEHM, a post-Newtonian (PN) inspiral waveform model for eccentric and spin-precessing compact binaries that includes higher-order modes and matter effects. Accurate and efficient waveform models capturing these effects are essential for probing compact-binary formation channels and exploiting current and future gravitational-wave (GW) observations. pyEFPEHM extends pyEFPE, significantly improving its physical content and accuracy. In particular, we show that above 2.5PN order the quasi-circular contributions to the orbital phasing dominate at each PN order, and incorporate all available higher-order quasi-circular PN corrections to the phasing, including adiabatic tidal effects. We generalize the multiple-scale analysis solution of the spin-precession equations, extending it to higher PN orders and including all available quasi-circular corrections. Finally, we add eccentric corrections up to 1PN order in the waveform amplitudes, including the GW multipoles $(l,|m|)=(2,2),(2,1),(2,0),(3,3),(3,2),(3,1),(3,0),(4,4),(4,2),(4,0)$. We validate pyEFPEHM against analytical waveform models and numerical relativity simulations, showing that it provides a robust and computationally efficient description of the inspiral, with good agreement across a broad region of parameter space and up to close to merger. The accuracy degrades in the late inspiral for systems with very unequal masses ($m_2/m_1 \lesssim 0.1$), significant spins aligned with the orbital angular momentum ($|\chi_\mathrm{eff}| \gtrsim 0.5$), and high eccentricities ($e \gtrsim 0.6$), where the PN expansion is expected to break down. pyEFPEHM represents a significant step toward physically complete and efficient waveform modeling of eccentric and precessing binaries, providing a foundation for future extensions including higher-order corrections, calibration to numerical relativity, and merger ringdown modeling.