Determining the range of validity of this thermodynamics is not a simple problem.

Krylov (1944) suggested that the property of *mixing* was
at the heart of the this question.

Quick (exponential) mixing leads to a short relaxation time. It results in strongly chaotic behaviour (positive Lyapunov exponent).

However, one can also have slower (power-law) mixing processes that are weakly chaotic.

The difference emerges because of short (long) ranged interactions and smooth (complex i.e. fractal/multifractal) boundary conditions.

Krylov N.
1944. *Nature* 153, 709.