English

Rotating black holes experience dynamical tides

General Relativity and Quantum Cosmology 2025-02-27 v2 High Energy Physics - Theory

Abstract

We find the dynamical tidal response of a Kerr black hole (BH) and demonstrate its tidal Love numbers to be non-vanishing when present in a non-axisymmetric external tidal field. To leading order, they depend quadratically on the black hole spin and linearly on the mode frequency. This implies that Kerr BHs are deformable under certain external, time-dependent perturbations. Since non-vanishing tidal Love numbers have been used in compact binary coalescences observed by the LIGO-Virgo-KAGRA (LVK) Collaboration to infer their non-BH nature, our findings have important implications on such inferences from future gravitational wave observations.

Keywords

Cite

@article{arxiv.2406.09543,
  title  = {Rotating black holes experience dynamical tides},
  author = {Rajendra Prasad Bhatt and Sumanta Chakraborty and Sukanta Bose},
  journal= {arXiv preprint arXiv:2406.09543},
  year   = {2025}
}

Comments

15 pages (with supplemental material), 1 figure

R2 v1 2026-06-28T17:05:14.974Z