Particle production due to a conformally coupled scalar field plus gravity in n+4 dimensions is considered. The metric for the gravitational field is taken to be a generalization of a Robertson-Walker metric. A general procedure for calculating the particle number density with any isotropically contracting compact space is developed. The number density is then calculated to lowest order in perturbation theory when the compact space is $T^n$ and examples are given.

• Received 10 June 1985

DOI:https://doi.org/10.1103/PhysRevD.32.3118