Radiationless transitions: Their effect on absorption line shapes and fluorescence decay curves

Radiationless transitions, and the interactions causing them, perturb absorption lineshapes and the time course of light emission. In this paper we use the standard model of a discrete state interacting with a continuum, but we allow the continuum density of states to assume various energy dependent forms. This energy dependence causes the absorption line shape to deviate from lorentzian in interesting ways. The emission decay curves may also become highly non-exponential, and show quantum beat effects in many situations.