The retardation effect is one of the classic problems in quantum theory of radiation which consider the delay of the energy transfer in terms of electromagnetic radiation between two atomic systems.

• 中文摘要在辐射场的量子论的领域中，延迟效应是一个相当典型的问题。该效应讨论在两原子的系统中，能量以电磁辐射的方式传递并且产生时间延迟。