Exactness of the mean-field dynamics in optical cavity systems

Validity of the mean-field approach to open system dynamics in the optical cavity system is examined. It is rigorously shown that the mean-field approach is justified in the thermodynamic limit. The result is applicable to nonequilibrium situations, e.g. the thermal reservoirs may have different temperatures, and the system may be subject to a time-dependent external field. The result of this work will lead to further studies on macroscopic open quantum systems.Comment: 29 pages, Published in J. Stat. Mech., the title is change