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

The direct current (DC) memory is a nonoscillatory, 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 harmonic coordinates and quasi-Keplerian parametrization by Ebersold et al. [Phys. Rev. D 100, 084043 (2019)], valid for nonspinning eccentric binaries, we provide the DC memory in terms of the effective-one-body (EOB) phase-space variables, up to the second and a half order in the post-Newtonian expansion and up to the sixth order in the small-eccentricity expansion. 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 themain features of the DC memory, also addressing its dependence on the eccentricity of the binary system at its formation.