Bounded Directional Complexity and Rigidity for ℤq-actions
摘要
We introduce directional complexities for ℤq-measure preserving dynamical systems via a collection of new metrics along non-zero directions in ℝq. It turns out that a ℤq-measure preserving dynamical system is rigid if and only if the invariant measure has bounded directional complexity. We also obtain ergodic decomposition formula for the measure-theoretic directional entropy of a ℤq-measure preserving dynamical system.