Functional approach to the schematic model of ''nuclear field theory''

Beyond the framework of perturbation teory derived are hamiltonian of nuclear field theory (NFT) and corresponding diagram rules. The conclusion is examplified by a schematic model with monopole partially-hole interaction. Effective lagrangian of NFT in terms of fermion and collective (phonon) fields taking account of their connection is obtained. With the aid of functional methods formulated is a modified perturbation theory in terms of collective fields, out of which NFT is built