An application of the light-front coupled-cluster method to the   nonperturbative solution of QED
  The new light-front coupled-cluster (LFCC) method for the nonperturbative solution of Hamiltonian eigenvalue problems is described and then illustrated in an application to quantum electrodynamics. The method eliminates any necessity for a Fock-space truncation and thereby avoids complications associated with such a truncation. An LFCC calculation of the electron's anomalous magnetic moment is formulated for a truncation that, for simplicity, excludes positrons but keeps arbitrarily many photons. 
S.S. Chabysheva, J.R. Hiller
hep-ph