Modal Interpretations and Relativity

Modal interpretations of quantum mechanics posit that the state vector obeys linear, unitary evolution at all times, and supplement the state vector with a set of possessed properties sufficiently rich to account for the occurrence of definite events at the macroscopic level, including definite outcomes of experiments, but sufficiently restricted so as to avoid a Kochen-Specker contradiction. The question arises whether this can be done within the restrictions imposed by special relativity. In a relativistic context, the notion of an instantaneous state of a spatially extended system must be replaced by the notion of a state on a spacelike hyperplane, or, more generally, a spacelike hypersurface. Since hyperplanes belonging to distinct foliations will intersect,