Abstract
The production of scalar particles in a homogeneous isotropic spatially flat universe containing classical baryons and radiation is studied for regulated massless free-field theories without trace anomalies. The pair-production probability is evaluated to lowest nonvanishing order in the parameter , where is the Planck length, is the baryon energy density, and is the radiation energy density, all in units where . For our universe . The back reaction regulates the production of scalar particles near the singularity so that the probability to produce a pair in the volume occupied by one baryon over the history of the universe is finite, of order of magnitude , where is the mass of a typical baryon, and therefore very small.
- Received 29 December 1980
DOI:https://doi.org/10.1103/PhysRevD.23.2121
©1981 American Physical Society