A generating functional for equal-time correlation functions

Our aim is to put the partially successful analytic noncovariant approaches to Coulomb gauge QCD on a firm and systematic basis. To this end, we develop a generating functional approach to the equal-time correlation functions. In fact, such a functional is given in terms of the vacuum wave functional, however, in a perturbative expansion of the equal-time correlation functions, the vacuum wave functional has to be known to the corresponding order. As a consequence, there are many contributions that correspond to one and the same Feynman diagram in the covariant theory. A remarkable simplification occurs on summing up these different contributions. We comment on the possibility of formulating new diagrammatic rules directly for the sum of all contributions that correspond to the same Feynman diagram.