My question is related to M. Alcubierres paper on the warp drive within general relativity. I was wondering about the realizability of this, setting the three energy conditions aside for the moment. Assuming the highest energy density known to me as an energy source, namely something like matter-antimatter fuel cells, is it necessary to actually release the energy in form for instance of annihilation processes in order to obtain curvature ? More precisely, how would I implement the stress-energy tensor in this scenario and how does it change between reaction, i.e. annihilation, and the bare storage of matter ?