Bosonic heat bath associated with a moving soliton in a fermionic system

When a soliton (such as a kink or vortex) in a condensed fermionic system moves, it produces particle-hole pairs. These approximately behave as a bosonic field, equivalent to a bath of harmonic oscillators and an effective bosonization of the fermion degrees of freedom very naturally arises. This work considers the theory of a moving soliton and an expression is given for the quantity, known as the spectral function, that characterises the effective bosons in the system. For a specific system possessing a soliton, the spectral function is evaluated