Affiliation:
1. University of Vienna
2. University of Oxford
3. Ludwig-Maximilians-Universität München
4. Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
Abstract
The propagation of gravitational waves can be described in terms of null geodesics by using the geometrical optics approximation. However, at large but finite frequencies the propagation is affected by the spin-orbit coupling corrections to geometrical optics, known as the gravitational spin Hall effect. Consequently, gravitational waves follow slightly different frequency- and polarization-dependent trajectories, leading to dispersive and birefringent phenomena. We study the potential for detecting the gravitational spin Hall effect in hierarchical triple black hole systems, consisting of an emitting binary orbiting a more massive body acting as a gravitational lens. We calculate the difference in time of arrival with respect to the geodesic propagation and find that it follows a simple power-law dependence on frequency with a fixed exponent. We calculate the gravitational spin Hall-corrected waveform and its mismatch with respect to the original waveform. The waveform carries a measurable imprint of the strong gravitational field if the source, lens, and observer are sufficiently aligned, or for generic observers if the source is close enough to the lens. We present constraints on dispersive time delays from GWTC-3, translated from limits on Lorentz invariance violation. Finally, we address the sensitivity of current and future ground detectors to dispersive lensing. Our results demonstrate that the gravitational spin Hall effect can be detected, providing a novel probe of general relativity and the environments of compact binary systems.
Published by the American Physical Society
2024
Funder
Science and Technology Facilities Council
National Science Foundation
Deutscher Akademischer Austauschdienst
Australian Research Council
Centre National de la Recherche Scientifique
Istituto Nazionale di Fisica Nucleare Sezione di Padova
Ministry of Education, Culture, Sports, Science and Technology
Japan Society for the Promotion of Science
National Research Foundation of Korea
Ministry of Science and ICT, South Korea
Academia Sinica
National Science and Technology Council
Max-Planck-Society
European Gravitational Observatory
Publisher
American Physical Society (APS)