Nontopological solitons from functional integrals. I

Abstract

We demonstrate a generalizable method for obtaining nontopological solitons from the functional-integral formulation of quantum field theory, with a view to eventually applying the techniques developed to model hadrons. We show that for the particular case of a scalar field interacting with a set of fermion fields this approach is equivalent to the quasiclassical approximation of Friedberg and Lee. It is advantageous to use the Euclidean formulation and to select the fermion numbers by introducing a set of independent chemical potentials for the fermion fields.