Results on the strong equivalence principle, dark matter, and new forces Original Research Article

Laboratory based torsion balance experiments allow sensitive tests of gravitational forces and of forces much weaker than gravity. Our EotWash group at the University of Washington has used torsion balances to set new limits on the equivalence principle and to probe new physics at very low energy scales. We present preliminary results that have implications for the strong equivalence principle, the interaction of ordinary matter with dark matter, and for limits on new forces between unpolarized and polarized matter.