Orbit capacity


In mathematics, orbit capacity of a subset of a topological dynamical system may be thought of heuristically as a “topological dynamical probability measure” of the subset. More precisely its value for a set is a tight upper bound for the normalized number of visits of orbits in this set.

Definition

A topological dynamical system consists of a compact Hausdorff topological space X and a homeomorphism. Let be a set. Lindenstrauss introduced the definition of orbit capacity:

Properties

When, is called small. These sets occur in the definition of the small boundary property.