DYNAMICAL GENERATION OF SPACETIME SIGNATURE BY MASSIVE QUANTUM-FIELDS ON A TOPOLOGICALLY NONTRIVIAL BACKGROUND

The effective potential for a dynamical Wick field (dynamical signature) induced by the quantum effects of massive fields on a topologically non-trivial D-dimensional background is considered. It is shown that when the radius of the compactified dimension is very small compared with LAMBDA1/2 (where LAMBDA is a proper time cut-off), a flat metric with Lorentzian signature is preferred on R4 x S1. When the compactification radius becomes larger a careful analysis of the one-loop effective potential indicates that a Lorentzian signature is preferred in both D = 6 and D = 4 and that these results are relatively stable under metrical perturbations.