  Recently, the time-reversal violation predicted for the pseudogap phase of
the cuprates, which was observed by dichroism experiments using Angle-Resolved
Photoemission has also been observed by polarized neutron diffraction. Earlier
derivation of dichroism in angle resolved photoemission due to time-reversal
violation relied on existence of mirror planes in the crystal. Here the theory
of the effect is generalized to the case that mirror plane symmetry is weakly
violated due to perturbing potentials such as a superstructure.
