Dynamics of fluctuations in non-Markovian systems
Daniel Alonso, Inés de Vega, E. Hernández-Concepción · Comptes Rendus Physique · 2007
The dynamics of multiple time correlation functions (MTCFs) of a system in contact with a non-Markovian environment is relevant in many different contexts. In this article we study the dynamical equations that satisfy MTCFs of a system and how they are used to characterize its fluctuations. The non-Markovian character of the interaction between the system and its environment leads to dynamical equations different from those derived from the Quantum Regression Theorem. We further discuss an stochastic method to compute MTCFs. To illustrate the theory we apply it to the evaluation of the emission spectrum of an atom in contact with a non-Markovian environment. The emission spectrum strongly depends on the way the environment reacts to the absorption of a photon emitted by the atom.