Thermodynamics without ergodicity

We show that fundamental thermodynamic relations can be derived from deterministic mechanics for a non-ergodic system. This extend a similar derivation for ergodic systems and suggests that ergodicity should not be considered as a requirement for a system to exhibit a thermodynamic behavior. Our analysis emphasizes the role of adiabatic invariants in deterministic description and strengthens the link between mechanics and thermodynamics. In particular, we argue that macroscopic thermodynamic behavior of a system is caused by the existence of different time scales in its deterministic microscopic evolution.