Scalar theories and symmetry breaking in the light-front coupled-cluster   method
  We extend the light-front coupled-cluster (LFCC) method to include zero modes explicitly, in order to be able to compute vacuum structure in theories with symmetry breaking. Applications to phi^3 and phi^4 theories are discussed as illustrations and compared with variational coherent-state analyses. 
S.S. Chabysheva
hep-ph