Non-Markovian interaction of many fields
  We study the interaction between several fields initially in coherent states. The solution allows us to explain why coherent states remain coherent states when subject to non-Markovian dissipation. We first study the interaction between two fields and show that this is the building block of the total interaction. We give a completely algebraic solution of this system. 
R. Mar-Sarao and H. Moya-Cessa