Dynamical tidal response of neutron stars: From effective field theory to gravitational waveforms
Abstract
We investigate the fully relativistic dynamical tidal response of neutron stars up to second order in the frequency. Combining the worldline effective field theory for extended gravitating bodies with perturbation theory of relativistic stellar models, we derive the tidal deformation induced by an external time-dependent field, including a universal logarithmic running term. In the effective theory, we work in dimensional regularization and, through a consistent matching procedure, obtain for the first time the complete leading-order dynamical tidal corrections to both the conservative dynamics and the gravitational-wave signal of compact binaries, including the scheme-dependent finite terms in addition to the running. We show that, in the relativistic regime, dynamical effects cannot be fully captured by mode excitations alone. The magnitude of the additional contribution depends on the stellar compactness, the equation of state, and the running term. Dynamical Love numbers are significantly enhanced with respect to their static counterparts for relatively small compactness. As a result, although they formally enter the gravitational-wave phase at eighth post-Newtonian order, dynamical tidal effects yield a nonnegligible contribution during the late inspiral. Using a Fisher-matrix analysis, we show that third-generation detectors such as the Einstein Telescope could measure dynamical Love numbers for a range of neutron-star masses and equations of state. Conversely, neglecting these effects can lead to significant biases in the inference of static Love numbers, and hence on the nuclear equation of state. Our results highlight the importance of dynamical tidal effects for high-precision gravitational-wave modeling with future detectors.
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BibTeX
@misc{apostolidis2026dynamical,
title = {{Dynamical tidal response of neutron stars: From effective field theory to gravitational waveforms}},
author = {Thomas Apostolidis and Valerio De Luca and Leonardo Gualtieri and Takuya Katagiri and Paolo Pani and Luca Santoni},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2606.19446},
eprint = {2606.19446},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.19446},
}
RIS
TY - UNPB
TI - Dynamical tidal response of neutron stars: From effective field theory to gravitational waveforms
AU - Thomas Apostolidis
AU - Valerio De Luca
AU - Leonardo Gualtieri
AU - Takuya Katagiri
AU - Paolo Pani
AU - Luca Santoni
PY - 2026
DA - 2026/09/22
PB - arXiv
DO - 10.48550/arxiv.2606.19446
UR - https://arxiv.org/abs/2606.19446
AB - We investigate the fully relativistic dynamical tidal response of neutron stars up to second order in the frequency. Combining the worldline effective field theory for extended gravitating bodies with perturbation theory of relativistic stellar models, we derive the tidal deformation induced by an external time-dependent field, including a universal logarithmic running term. In the effective theory, we work in dimensional regularization and, through a consistent matching procedure, obtain for the first time the complete leading-order dynamical tidal corrections to both the conservative dynamics and the gravitational-wave signal of compact binaries, including the scheme-dependent finite terms in addition to the running. We show that, in the relativistic regime, dynamical effects cannot be fully captured by mode excitations alone. The magnitude of the additional contribution depends on the stellar compactness, the equation of state, and the running term. Dynamical Love numbers are significantly enhanced with respect to their static counterparts for relatively small compactness. As a result, although they formally enter the gravitational-wave phase at eighth post-Newtonian order, dynamical tidal effects yield a nonnegligible contribution during the late inspiral. Using a Fisher-matrix analysis, we show that third-generation detectors such as the Einstein Telescope could measure dynamical Love numbers for a range of neutron-star masses and equations of state. Conversely, neglecting these effects can lead to significant biases in the inference of static Love numbers, and hence on the nuclear equation of state. Our results highlight the importance of dynamical tidal effects for high-precision gravitational-wave modeling with future detectors.
ER -