Could dark matter trapped inside neutron stars make them wobble?

Dark matter accumulating inside a neutron star could create an asymmetric lump — a 'dark mountain' — that makes the star wobble and emit continuous gravitational waves. Using LIGO's third observing run, this analysis places the first limits on how much dark matter deformation is allowed, ruling out self-interaction couplings stronger than roughly 10⁻⁵·⁵ for nearby stars. Next-generation detectors like Einstein Telescope could push these limits ten times deeper.