S-Expansiveness and Zip Shift Maps in Symbolic Dynamics
S. Lamei, P. Mehdipour, W. Vargas
TL;DR
The paper addresses how to characterize S-expansiveness for local homeomorphisms and to represent such dynamics symbolically via zip shift maps. It develops the inverse limit framework $X^f$ and the bilateral extension $\tilde{f}$, introduces $m$-to-1 local homeomorphisms, and uses generators and topological partitions to link expansivity to symbolic coding. The main contributions show that zip shift maps are S-expansive and possess the shadowing property, and that any S-expansive local homeomorphism $f$ is a factor of a zip shift map through a surjection $\pi:\Sigma\to X$ with $\pi\circ\sigma_{\tau}=f\circ\pi$. This establishes a universal symbolic model for a broad class of non-invertible systems and clarifies how expansive behavior can be captured by zip shifts.
Abstract
In this paper, we introduce the concept of S-expansiveness for local homeomorphisms and demonstrate that a class of extended symbolic dynamics, known as zip shift maps, are S-expansive and possess the shadowing property. Furthermore, we prove that any S-expansive local homeomorphism is a factor of a zip shift map.
