I am impressed with authoring on Warp Engines, but would like to offer an alternative of what I see as a dark matter engine - Dark Matter Engine .
It is conceptual, and does not assume warping, light speed or otherwise. It it summerized as follows -
"To create and manipulate a Black Body Radiator within a chamber in order to create propulsion from directing its radiation. Within the engine's chamber, a heating element ( based on design ) is used with the absolute cold of space. This is to create the black body radiator within the chamber. The radiation from the radiator is to be compressed and directed magnetically to faciliate a direction of heat flow of the heating element. In creating a difference of a low and high pressure space, overcoming inertia is achieved for the engine. "
The bottom line is, that I see it as do-able !
Regards,
Orion -