Path-integral approach to the statistical mechanics of solitons

Universal features for the statistical mechanics of a general class of systems with a one-component field in one dimension have been obtained using path-integral techniques in a physically revealing and more direct way than was possible before from the transfer-operator method. Results are also extended to systems that can support more than one type of soliton. Spin-wave and soliton contributions are calculated simultaneously, thus enabling us to investigate the relative importance of spin-wave and soliton contributions in a given physical quantity. These general results are then applied to the double-sine-Gordon model. We discuss the statistical-mechanical properties of the model as the parameters are varied. Assessments of the validity of our results are also made.