Tests of the Gravitational Inverse-Square Law below the Dark-Energy Length Scale

We conducted three torsion-balance experiments to test the gravitational inverse-square law at separations between 9.53 mm and 55μm, probing distances less than the dark-energy length scale λ_d=ℏc/ρ_d4≈85μm. We find with 95% confidence that the inverse-square law holds (|α|≤1) down to a length scale λ=56μm and that an extra dimension must have a size R≤44μm.