Negative Energy Densities and the Limit of Classical Space-Time
arXiv:gr-qc/9806081 · doi:10.1142/S0217732398001716
Abstract
Although negative energy densities are predicted by relativistic quantum field theories, I present an argument that an "operational" positivity still holds: the energy in a region, plus the energy of an isolated device which traps or measures that energy, must be positive. If we assume Einstein's field equation, this means the local geometry of a negative energy-density region cannot be measured by the trajectories of test particles. So far, all attempts to design thought-experiments to verify a classical local geometry in the negative energy-density region have failed. It seems we must impute a quantum character to such a space-time regime.
8 pages, plain Tex, no macros needed, 1998 G.R.F. Honorable Mention, to appear in Mod. Phys. Lett. A