Production of massive particles during reheating - art. no. 063504.

What is commonly called the reheat temperature, T-RH, is not the maximum te mperature obtained after inflation. The maximum temperature is, in fact, mu ch larger than T-RH. As an application of this we consider the production o f massive stable dark-matter particles of mass M-X during reheating, and sh ow that their abundance is suppressed as a power of T-RH/M-X rather than ex p(-M-X/T-RH). We find that particles of mass as large as 2x10(3) times the reheat temperature may be produced in interesting abundance. In addition to dark matter, our analysis is relevant for baryogenesis if the baryon asymm etry is produced by the baryon (or lepton) number violating decays of super heavy bosons, and also for relic ultra-high energy cosmic rays if decays of superheavy particles are responsible for the highest energy cosmic rays. [ S0556-2821(99)07918-7].