Some properties of microcanonical rate constants

An isolated body is characterized by conserved properties such as its energy and angular momentum. The rates of processes occurring in that body can thus be investigated as a function of these properties. On the other hand the rates may be better known, both conceptually and experimentally, as a function of temperature. This paper surveys relations between rate descriptions in the two domains, as deduced using steepest descent techniques. The rudiments of these techniques are given in an appendix.