Worldline Influence Functional: Abraham-Lorentz-Dirac-Langevin Equation from QED

摘要

We present a stochastic theory of charges moving in an electromagnetic fieldusing nonequilibrium quantum field theory. We give a first principles'derivation of the Abraham-Lorentz-Dirac-Langevin equation which depicts thequantum expectation value for a particle's trajectory and its stochasticfluctuations by combining the worldline path integral quantization with theFeynman-Vernon influence functional or closed-time-path effective actionmethods. At lowest order, the equations of motion are approximated by astochastic Lorentz-Dirac equation.