Heat conduction in one-dimensional nonintegrable systems

Two classes of one-dimensional nonintegrable systems represented by the Fermi-Pasta-Ulam (FPU) model and the discrete [Formula Presented] model are studied to seek a generic mechanism of energy transport on a microscopic level sustaining macroscopic behaviors. The results enable us to understand why the class represented by the [Formula Presented] model has a normal thermal conductivity and the class represented by the FPU model does not even though the temperature gradient can be established.