Interferometry in a space-time with torsion

Summary

The phase shift in neutron interference due to the gravitational field containing torsion is obtained, by using a WKB approximation of Dirac’s equation. It is then shown that, an upper limit on torsion of about 1^-7 m^-1 may be placed, for the first time, in principle, by neutron interferometry. This phase shift can also be obtained by a path-ordered operator, which is an element of the anti-De Sitter group SO_3,2 that determines the evolution of the wave function. This is somewhat analogous to the determination of the corresponding phase shift for gauge fields by means of parallel transports which are elements of the gauge group.