Dr. Harold Wilson is on the
X-Physics Propulsion & Power Project (XP4) for the
Icarus Interstellar Project. Their mission, according to Icarus International:
Implementation of FTL interstellar travel via space warps generally requires the engineering of spacetime into very specialized local geometries. The analysis of these via General Relativity plus the resultant equations of state demonstrate that such geometries require the use of exotic matter fields. The natural and phenomenological forms of exotic matter include; squeezed quantum vacuum states (includes the class of Casimir vacuum states), Gravitationally redshifted or gravitationally squeezed quantum vacuum states, Casimir vacuum energy, Cosmological inflation, dark energy/cosmological constant, phantom energy and others.
Current theoretical efforts regarding space warp geometries typically focus on exploring novel spacetime metrics and their associated properties. Experimental work is currently limited, but typically centers around studying Casimir vacuum energy. Interestingly, recent advances in the field of Metamaterial (artificial materials engineered to have properties not found in nature) have allowed for the possibility of simulating exotic metrics in the lab.
Salient issues that have been identified, and that motivate further research include:
Quantum back reaction effects in 3+1 dimensional spacetimes
Casual disconnection and controlling warp bubbles from bubble interior
Examination of quantum inequality restrictions for wormholes
Issues of causality and the temporal paradoxes
Experimental metric modeling via metamaterials

Artist's drawing of an FTL starship