Electric current in a translation invariant environment

The master equation for the reduced density matrix of a charged particle interacting with a translation invariant weakly coupled environment is considered. The electric current is renormalized by the systemenvironment interaction, leading to a direct signature of the environment in the bremsstrahlung. The general solution is given in the absence of the external electromagnetic field, and the spread and the decoherence of a wave packet are followed. The increased complexity and importance of the boundary conditions for the density matrix are pointed out.

Automated summary

The master equation for the reduced density matrix of a charged particle interacting with a translation invariant weakly coupled environment is studied. The renormalization of electric current by the system-environment interaction leads to a direct manifestation of the environment in the bremsstrahlung. The general solution is provided in the absence of an external electromagnetic field, and the spread and decoherence of a wave packet are analyzed.