T-violation and the dark sector

Abstract

It is argued, as a working hypothesis, that “normal” and dark matter interactions can only be [Formula: see text]- and [Formula: see text]-violating. One way to implement this idea is to consider that time reversal in dark matter is implemented, not by an antiunitary operator, but by an unitary operator. It is shown how this occurs naturally in the context of complex spacetime with an extended symmetry group.