0 Cooperative Electromagnetic Effects

Collective phenomena in strongly nonequilibrium systems interacting with electromagnetic field are considered. Such systems are described by complicated non-linear differential or integro–differential equations. The aim of this review is to show that many nonlinear collective phenomena can be successfully treated by a recently developed method called the Scale Separation Approach whose name is due to the idea of separating different characteristic space–time scales existing in nonequilibrium statistical systems. This approach is rather general and can be applied to various nonequilibrium physical problems, several of which are discussed here. The problems considered not only serve as illustrations of the method but are quite important by themselves presenting interesting physical effects, such as