Light dark matter scattering in gravitational wave detectors

We present prospects for discovering dark matter scattering in gravitational wave detectors. The focus of this work is on light, particle dark matter with masses below 1 $$\hbox {GeV}/\text {c}^{2}$$ GeV / c 2 . We investigate how a potential signal compares to typical backgrounds like thermal and quantum noise, first in a simple toy model and then using KAGRA as a realistic example. That shows that for a discovery much lighter and cooler mirrors would be needed. We also give some brief comments on space-based experiments and future atomic interferometers.