Generating Functional for Bound States in QED
  The manifestly Lorentz covariant formulation of quantum electrodynamics disregards Coulomb instantaneous interaction and its consequence - instantaneous bound states (IBS's). In this article we consider the way of construction the IBS generating functional using the operator generalization of the initial data in the Dirac Hamiltonian approach to QED. 
M. Piatek, V.N. Pervushin, A.B. Arbuzov