Quantum Stress Tensor Fluctuation Effects in Inflationary Cosmology
  We review several related investigations of the effects of the quantum stress tensor of a conformal field in inflationary cosmology. Particular attention will be paid to the effects of quantum stress tensor fluctuations as a source of density and tensor perturbations in inflationary models. These effects can possibly depend upon the total expansion factor during inflation, and hence be much larger than one might otherwise expect. They have the potential to contribute a non-scale invariant and non-Gaussian component to the primordial spectrum of perturbations, and might be observable. 
Jen-Tsung Hsiang, Chun-Hsien Wu, L.H. Ford and Kin-Wang Ng
gr-qc astro-ph.CO hep-th