When Periodicity Fails to Guarantee the Existence of Rotation: A Counterexample on $\mathbb{T}^3$

Abstract

In this manuscript, we construct an explicit counterexample of a smooth \(C^{\infty}\), periodic dynamical system on the torus \(\mathbb{T}^3\) for which the rotation vector exists in a weak sense, but fails to exist in the strong sense of bounded deviation (also referred to as {\it {frequencies}} in parts of the physics and biology literature). The construction exploits Liouville-type arithmetic properties and demonstrates that smoothness and periodicity alone do not ensure bounded deviation, even within the class of integrable systems.