Beyond Unruh Effect: Nonequilibrium Quantum Dynamics of Moving Charges
  We discuss some common misconceptions in Unruh effect and Unruh radiation for the cases of linear and circular uniform acceleration of a charged particle or detector moving in a quantum field. We point to the need to go beyond Unruh effect and develop a new theoretical framework for treating the stochastic dynamics of particles interacting with quantum fields under more general nonequilibrium conditions. This framework has been established in recent years using the influence functional formalism and applied to relativistically moving charged particles. Only with nonequilibrium concepts and methodology applied to particle-field interaction can one grasp the full complexity of the problems of beam physics under more realistic conditions, from electrons and heavy ions to coherent atoms. 
B.L. Hu and Philip R. Johnson