Wrapped Floer homology and hyperbolic sets
Rafael A. Fernandes
TL;DR
This work establishes a direct link between a Floer-theoretic invariant, the wrapped Floer homology barcode entropy, and deterministic chaos measures of the Reeb flow on the boundary of a Liouville domain. By defining and leveraging a relative framework, the authors prove that, in the presence of a locally maximal hyperbolic set $K$ for the Reeb flow, the barcode entropy $\hbar^{HW}$ satisfies $\hbar^{HW}(M,L_0 \rightarrow L_1) \ge h_{top}(K)$. The core methodology combines the filtered wrapped Floer homology construction with a pair of dynamical-analytic results, the Crossing Energy Theorem (with boundary conditions) and the Location Constraint, to translate low-energy Floer data into exponential growth dictated by hyperbolic dynamics. This demonstrates that barcode entropy captures local dynamical complexity independent of global topology or filling, linking Floer-theoretic invariants to classical dynamical entropy and providing a robust tool for probing chaotic Reeb dynamics through symplectic topology.
Abstract
In this paper, we continue the quest to understand the interplay between wrapped Floer homology barcode and topological entropy. Wrapped Floer homology barcode entropy is defined as the exponential growth, with respect to the left endpoints, of the number of not-too-short bars in its barcode. We prove that, in the presence of a topologically transitive, locally maximal hyperbolic set for the Reeb flow on the boundary of a Liouville domain, the barcode entropy is bounded from below by the topological entropy restricted to the hyperbolic set.
