Gravitational vacuum polarization
arXiv:gr-qc/9710034
Abstract
The energy conditions of classical Einstein gravity fail once quantum effects are introduced. These quantum violations of the energy conditions are not subtle high-energy Planck scale effects. Rather the quantum violations of the energy conditions already occur in semiclassical quantum gravity and are first-order O(\hbar) effects. Quantum violations of the energy conditions are widespread, albeit small.
Three pages, uses mprocl.sty To appear in the proceedings of the Eighth Marcel Grossmann Conference on General Relativity. (Jerusalem, Israel, June 1997) [Minor typo fixed in references.]