POSSIBILITY OF MASSIVE LUMINAL-TYPE OBJECTS

The propagation of matter waves in the expanding space-time continuum is considered in the framework of de Broglie's causal interpretation o f quantum mechanics. It is shown that in the Robertson-Walker-de Sitte r space a particle of mass 3HhBAR/2c2, strictly related to the Hubble parameter H, is endowed with luminal-type characteristics, that is, it has an effective zero rest mass, and the associated matter waves prop agate as nonlinear light-type excitations. Our analysis also indicates the possibility of appearance of spacelike objects with real rest mas s moving at a superluminal velocity.