Stochastic Lineshape Theory for Multistate, Non-Markovian Frequency Fluctuations#.

A stochastic lineshape theory is formulated for the non-Markovian and multistate frequency modulation model. The frequency of the stochastic oscillator undergoes non-Markovian modulations between multiple states, and the transition processes are described by arbitrary waiting-time distributions. By incorporating stationarity into the stochastic process in a proper way, we calculate the propagator and the relaxation function. It is shown that a stationary distribution among the oscillator states satisfies a generalized detailed balance condition even in the non-Markovian case. We find an exact expression for the lineshape function, which contains the Markovian case as a special limit. [ABSTRACT FROM AUTHOR]