This does assume that the higgs boson is real and we can come up with a way of manipulating it at relatively low power levels. Not much good in the short term i

This does assume that the higgs boson is real and we can come up with a way of manipulating it at relatively low power levels. Not much good in the short term if it takes the power output of a star to achieve :) Alastair Reynolds' Revelation Space series of hard sci-fi has quite a bit about ships called Lighthuggers that basically travel at about 0.95c and exploit relativity to achieve short journeys for crew members when hundreds of years pass in the real world. A more advanced technology in the books is one which reduces the inertia of an object to achieve even higher speeds, the higgs isn't mentioned explicitly IIRC but I think it's what the books are getting at.