Coherent infrared representations in non-relativistic QED
  We consider dressed 1-electron states in a translation-invariant model of non-relativistic QED. To start with a well-defined model, the interaction Hamiltonian is cutoff at very large photon energies (ultraviolet cutoff) and regularized at very small photon energies (infrared regularization). The infrared regularization is then removed, and the representations of the canonical commutation relations of the electromagnetic field operators determined by the dressed 1-electron states are studied using operator-algebra methods. A key ingredient in our analysis is a bound on the renormalized electron mass uniform in the infrared regularization. Our results have important applications in the scattering theory for infraparticles. 
Thomas Chen and Juerg Froehlich