Fixed Point Methods and Optimization

Electronic ISSN: 3008-1548

DOI: 10.69829/fpmo

Variational principle for unstable packing topological entropy

Fixed Point Methods and Optimization, Volume 2, Issue 2, August 2025, Pages 149–157

TIANKUI LUO

College of Mathematics and Statistics, Chongqing Jiaotong University, Chongqing, China 400074

CHENSHI ZHOU

College of Mathematics and Statistics, Chongqing Jiaotong University, Chongqing, China 400074

WENDA ZHANG

College of Mathematics and Statistics, Chongqing Jiaotong University, Chongqing, China 400074


Abstract

In this paper we define unstable packing topological entropy \(h_{p}^{u}(f,Z)\) for any subsets (not necessarily compact or invariant) in partially hyperbolic dynamical systems as a packing dimension characteristic, and the unstable measure theoretical upper entropy \(\overline{h}^{u}_{\mu}(f)\) for any \(\mu\in\mathcal{M}(M)\), where \(\mathcal{M}(M)\) denotes the collection of all Borel probability measures on \(M\). For any non-empty compact subset \(Z\subseteq M\), we will prove a variational principle for unstable packing topological entropy: for any Borel subset \(Z\) of \(M\), the unstable packing topological entropy of \(Z\) equals the supremum of unstable measure theoretical upper entropy over all Borel probability measures for which the subset \(Z\) has full measure.


Cite this Article as

Tiankui Luo, Chenshi Zhou and Wenda Zhang, Variational principle for unstable packing topological entropy, Fixed Point Methods and Optimization, 2(2), 149–157, 2025