In the conclusions section, there is reference to "three conjectures on how one might enhance energy-
momentum to spacetime curvature coupling" - which might be shortened to something like "e-m gravity coupling", but that EM is not the same as electromagnetic EM.<p>Idk, it's kind of cool, smashing two plasma rings into each other, and not implausible that that might push the obtainable energy densities up by "orders of magnitude", but it's hard to see how this is about electric/gravity interactions.