Gravitophoton Field Propulsion, or simply Field Propulsion, is a theoretical propulsion method based on the Heim-Dröscher extension of Heim Quantum Theory, which predicts two additional fundamental forces and their carrier particles to the four experimentally known (electromagnetism, strong nuclear force, weak nuclear force, and gravity) which would allow the transformation of electromagnetic radiation into a gravity-like field.
A Field Propulsion engine would make use of a rapidly rotating torus within a powerful radial magnetic field to generate a Heim-Lorentz Force, an analogue to the Lorentz Force which acts on all mass rather than just charged particles. Field propulsion is also potentially bi-modal, allowing both normal acceleration through space in stage one and superluminal travel in stage two.
In a Field Propulsion engine, the high-intensity magnetic field acts as a catalyst for the transformation of virtual photons into pairs of positive and negative gravitophotons. The simultaneous production of positive (repulsive) and negative (attractive) particles means that zero net energy is extracted from the vacuum. While the positive and negative gravitophotons produce opposing forces on interaction with matter, the interaction cross-section of positive gravitophotons is predicted to be much lower than that of negative gravitophotons, resulting in a net acceleration of the vehicle. Thus, in stage one, the Field Propulsion engine is essentially a Differential Sail powered by vacuum fluctuations. In order to maximize the force produced, the optimal torus material for stage one operation is hydrogen, but engineering difficulties would mostly likely require a hydrogen-rich solid compound. A Field Propulsion engine is not strictly a reactionless drive, as a reaction force is produced by the expulsion of positive gravitophotons from the system (analogous to a photon rocket), but it can practically be considered a reactionless space drive as it requires no propellant and does not push on anything external to itself.
In order to use a Field Propulsion engine for superluminal travel, different aspects of the gravitophoton field must be emphasized, requiring different optimal torus materials in stage two than in stage one. When positive gravitophotons interact with gravitons produced by the vehicle's mass, they are converted into the second new particle predicted by Heim-Dröschler Quantum Theory, vaccuum or quintessence particles carrying a repulsive force, thus reducing the vehicle's gravitational potential and apparent mass. To satisfy conservation of linear momentum, this reduction in apparent mass must be accompanied by an increase in speed. Normally, this would require a local alteration in the value of c (c' > C) or G (G' < G). As this is impossible within the space described by Heim Quantum Theory, it is postulated that the vehicle will transition into a parallel space with covariant physical laws but appropriately scaled physical constants. For a value of c' = nc, the vehicle would transition into nth-parallel space, where n is quantized to integer values. Thus, transitioning will only occur above a certain gravitophoton field strength threshold with successive transitions occuring in discreet steps. The theoretical maximum value for n is 6.6e10. Upon shutting off the field, the vehicle would retransition back into normal space, having traveled a distance of nvt, where v is the vehicle's velocity in normal space and t is the time spent in parallel space.
NOTE: It seems to me that stage two (superluminal mode) suffers from frame invariance problems. However, I find it unlikely that all of the papers on the subject could have so far gotten by without anybody involved noticing this, if it is a real problem. So, I'm confident that there is an explanation (maybe there really is some preferred frame for parallel space transitions?), but I have no idea what it is at this time.