MINIMAL COUPLING AND THE EQUIVALENCE PRINCIPLE IN QUANTUM-MECHANICS

The role of the Equivalence Principle (EP) in classical and quantum me chanics is reviewed. It is shown that the weak EP has a counterpart in quantum theory, a Quantum Equivalence Principle (QEP). This implies t hat also in the quantum domain the geometrization of the gravitational interaction is an operational procedure similar to the procedure in c lassical physics. This QEP carl be used for showing that it is only th e usual Schrodinger equation coupled to gravito-inertial fields which obeys our equivalence principle, In additions the QEP applied to a gen eralized Pauli equation including spin results in a characterization o f the gravitational fields which call be identified with the Newtonian potential and with torsion. Also, in the classical limit it is possib le to state beside the usual EP for the path an EP for the spill which again may be used for introducing torsion as a gravitational field.