TESTING THE EQUIVALENCE PRINCIPLE IN THE QUANTUM REGIME

We consider possible tests of the Einstein Equivalence Principle for p hysical systems in which quantum-mechanical vacuum energies cannot be neglected. Specific tests include a search for the manifestation of no n-metric effects in Lamb-shift transitions of hydrogenic atoms and in anomalous magnetic moments of massive leptons. We discuss how current experiments already set bounds on the violation of the equivalence pri nciple in this sector and how new (high-precision) measurements of the se quantities could provide further information to this end.