Bohr chaoticity of topological dynamical systems
Résumé
We introduce the notion of Bohr chaoticity, which is a topological invariant for topological dynamical systems, and which means that the system is not orthogonal to any non-trivial weights. We prove the Bohr chaoticity for all systems which have a horseshoe and for all toral affine dynamical systems of positive entropy, some of which don’t have a horseshoe.