NONPERTURBATIVE COLLECTIVE FIELD-THEORY

We present a non-perturbative framework for collective field theory. Two methods are given. In the first exact Fock space states diagonalizing the hamiltonian are described. Based on these, effective lagrangians are introduced. An extra single-particle branch is pointed out. It is shown that the states of this new branch correspond to solitons, the semiclassical soliton solutions are seen to take the form of a single eigenvalue effect. In general we argue that single (complex) eigenvalues will lead to solitons while real eigenvalues give instanton configurations.