Jie Sheng, "Weak-Equivalence-Principle Tests as Detectors for Coherent Dark Matter Scattering"
Light dark matter can scatter coherently from macroscopic test masses, producing tiny accelerations that mimic violations of the weak equivalence principle. In this talk, I will discuss how precision equivalence-principle experiments can be reinterpreted as detectors for light dark matter. I will first introduce the coherent enhancement mechanism for sub-eV dark matter scattering from macroscopic targets and the resulting constraints from asymmetric torsion-balance experiments. I will then describe how intrinsic density fluctuations in heterogeneous materials extend the coherent response to higher dark-matter masses, allowing MICROSCOPE data to probe previously unexplored sub-keV parameter space. Together, these results open a new avenue for searching for light dark matter with high-precision tests of gravity.