- Featured in Physics
- Editors' Suggestion
Dynamical Response of Viscous Objects to Gravitational Waves
Phys. Rev. Lett. 135, 151402 – Published 8 October, 2025
DOI: https://doi.org/10.1103/smlr-v7b2
Abstract
We study the dynamical response of viscous materials to gravitational waves, in the context of a fully relativistic theory of fluid dynamics. For the first time, we calculate oscillation modes and scattering properties of viscous stars. Viscous stars absorb high-frequency radiation, following a dispersion relation introduced by Press. In the extremely large viscosity regime, stars would become reflectors of waves, but this regime appears to be forbidden by causality bounds. In the context of black hole mimickers, we show how maximally viscous stars on the threshold of stability mimic the absorption of a black hole with the same mass. Our results suggest that rotating viscous stars will amplify incoming radiation.
Physics Subject Headings (PhySH)
Collections
This article appears in the following collection:
PRL Collection of the Year 2025
For the second year in a row, our editors have curated a set of some of the best papers from the wide range of topics PRL covers in fundamental and applied physical science. Congratulations to all the authors in this collection!
Viewpoint
Viscous Stars Can Reflect Gravitational Waves like Black Holes Do
A neutron star’s viscosity determines how the star interacts with gravitational waves, a behavior that could be useful to the study of neutron-star interiors.
See more in Physics
