Direct current memory effects in effective-one-body waveform models

TL;DR

This paper introduces the first effective-one-body (EOB) waveform model that includes direct current (DC) memory effects, enhancing the accuracy of gravitational wave signals by accounting for nonlinear hereditary components.

Contribution

The work transforms existing DC memory results into EOB variables and implements them in a new waveform model, enabling more precise gravitational wave predictions.

Findings

First EOB model with DC memory effects.

Quantified impact of DC memory on waveforms.

Analyzed dependence of memory on binary eccentricity.

Abstract

The direct current (DC) memory is a non-oscillatory, hereditary component of the gravitational wave (GW) signal that represents one of the most peculiar manifestations of the nonlinear nature of GW emission and propagation. In this work, by transforming the results provided in Ebersold et al. [Phys.Rev.D 100 (2019) 8, 084043] in harmonic coordinates and quasi-Keplerian parametrization, we provide the DC memory in terms of the effective-one-body (EOB) phase-space variables, with a relative accuracy of 2.5PN and in an expansion for small eccentricity up to order six. Our results are then implemented in TEOBResumS-Dal\'i, thus providing the first EOB model with DC memory contributions. This model is then used to assess the impact on the waveform and the main features of the DC memory, also addressing its dependence on the eccentricity of the binary system at its formation.