Vacuum instability and gravitational collapse
arXiv:hep-th/0211037
Abstract
We argue that heterotic string models with 4 non-heterotic spacetime dimensions may provide an instability of the vacuum to gravitational polarization in globally strong gravitational fields. This instability would be triggered during gravitational collapse by a non-local quantum switching process, and lead to the formation of regions of a high temperature broken symmetry phase which would be the equivalent in these string models of conventional black holes.
17 pages, LaTeX 2e. v2 Corrected argument in section 2, typos fixed