Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2508.17800

Variations of topological theory and ergodic theory via gap function in non-uniform specification

Wanshan Lin·Xueting Tian·Chenwei Yu
View original source ↗Read source document ↗Export metadata ↓

Abstract

In our previous work [43], we studied qualitative differences between specification and nonuniform specification. In this paper, we investigate quantitative variations governed by the gap function. We first obtain lower bounds for the Bowen topological entropy of irregular sets in terms of the lower linear growth of gap function. In contrast, we prove that every non-empty over-saturated set has full packing topological entropy under non-uniform specification. We also establish a quantitative lower bound for the Bowen topological entropy of transitive points under non-uniform specification, and a lower bound for the exponential growth of periodic orbits under its periodic version. Besides, we construct symbolic systems with a given gap growth which contain an arbitrary subshift. These systems show that the bounds concerning irregular sets and periodic orbits are optimal. They also show that positive linear gap growth may destroy full Bowen entropy of transitive points, the conditional variational principle, the intermediate entropy and pressure properties, and the genericity of continuous functions whose unique maximizing measure has zero entropy.

Explore related subjects

math.DS

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Wanshan Lin, Xueting Tian, Chenwei Yu. 2025-08-25. Variations of topological theory and ergodic theory via gap function in non-uniform specification. https://arxiv.org/abs/2508.17800

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Admissible Fourier Lengths, KAM Reducibility, and Spectral Applications

We develop a perturbative KAM reducibility theory for one-frequency $\mathrm{SL}(2,\mathbb{R})$ cocycles based on an admissible Fourier length $\ell$. The regularity relevant to the iteration is measured by positive adapted Fourier width rather than ordinary smoothness in the Euclidean length $|n|$. The same length governs Fourier decay, truncation and resonance scales, and the arithmetic condition controlling the small divisors. This framework contains the classical analytic and Gevrey settings, while non-monotone choices of $\ell$ allow classical nowhere differentiable Weierstrass-type perturbations and continuous perturbations outside every positive H\"older class. As spectral applications, we obtain purely absolutely continuous spectrum for every phase and $1/2$-H\"older continuity of the integrated density of states for the associated quasiperiodic Schr\"odinger operators. The Aubry dual has pure point spectrum for Lebesgue almost every dual phase, with eigenfunctions exponentially localized in the metric induced by $\ell$. We also construct nowhere differentiable quasiperiodic potentials with purely absolutely continuous Cantor spectrum.

math.DS↗
arXiv2026

Dynamics inside the attracting basins of some skew products

Polynomial skew products in $\mathbb{C}^2$ are maps of the form $F(z,w)=(P(z),Q(z,w))$, where $P$ and $Q$ are polynomials. Their local dynamics have been widely investigated. In this paper, we study the global dynamics inside Fatou components of some skew products. We consider all the inverse images in a Fatou component of a given point and use the Kobayashi metric to measure the distance between points. In the cases we consider, there are always arbitrarily large Kobayashi balls in the complement of these inverse sets.

math.DS↗
arXiv2026

Ergodicity of dynamical systems without uniqueness of orbits

Recently, there has been considerable interest in the study of non-deterministic dynamical systems. To analyze the chaotic behavior of such systems from a measure-theoretic viewpoint, it is desirable to consider ergodicity. However, the classical definition of ergodicity involves invariant sets, whose definition is not unique for non-deterministic dynamical systems. Thus, we are led to the question of which invariance yields an interesting definition of ergodicity. Here, we propose a definition based on the strong backward invariance and show that analogs of classical results hold. We also consider implications of the Birkhoff ergodic theorem for systems without uniqueness of orbits.

math.DS↗