COSMOLOGICAL CONSEQUENCES OF PARTICLE CREATION DURING INFLATION

Particle creation during inflation is considered. It could be importan t for species whose interaction is of gravitational strength or weaker . A complete but economical formalism is given for spin-zero and spin- half particles, and the particle abundance is estimated on the assumpt ion that the particle mass in the early universe is of the order of th e Hubble parameter H. It is roughly the same for both spins, and it is argued that the same estimate should hold for higher spin particles, in particular, the gravitino. The abundance is bigger than that from t he usual particle collision mechanism if the inflationary energy scale is of the order of 10(16) GeV, but not if it is much lower.