We introduce IMRPhenomTEHM, a new phenomenological time-domain model for eccentric aligned-spin binary black holes. Building upon the accurate quasi-circular IMRPhenomTHM model, IMRPhenomTEHM integrates the eccentric post-Newtonian (PN) dynamics and introduces eccentric corrections into the waveform multipoles up to 3PN, including spin effects. The model incorporates the dominant (2, ±2) spherical harmonic mode, as well as the subdominant modes (2, ±1), (3, ±3), (4, ±4), and (5, ±5), assuming the binary has circularized by the time of merger. This approach ensures a smooth transition to the non-eccentric limit, providing an accurate quasi-circular limit against the IMRPhenomTHM model. When comparing against 28 public eccentric numerical relativity simulations from the Simulating eXtreme Spacetimes catalog, IMRPhenomTEHM achieves lower than 2% unfaithfulness, confirming its accurate description without calibration to numerical relativity eccentric datasets. IMRPhenomTEHM provides a reliable description of the evolution of eccentric black hole binaries with aligned spins and eccentricities lower than e=0.4 at a frequency of 10 Hz, making it suitable for upcoming gravitational-wave observing runs. We validate the model's accuracy through parameter estimation studies, recovering injected parameters within 90% credible intervals for three numerical relativity eccentric simulations and reanalyzing GW150914 and GW190521, obtaining results consistent with the literature.
@article{arxiv.2503.13062,
title = {Time-domain phenomenological multipolar waveforms for aligned-spin binary black holes in elliptical orbits},
author = {Maria de Lluc Planas and Antoni Ramos-Buades and Cecilio García-Quirós and Héctor Estellés and Sascha Husa and Maria Haney},
journal= {arXiv preprint arXiv:2503.13062},
year = {2026}
}