English

Local intricacy and average sample complexity for amenable group actions

Dynamical Systems 2025-09-26 v1

Abstract

Let (X,G)(X,G), (Y,G)(Y,G) be two GG-systems, where GG is an infinite countable discrete amenable group and XX, YY are compact metric spaces. Suppose that U\mathcal{U} is a cover of XX. We first introduce the conditional local topological intricacy Inttop(G,UY)\mathrm{Int}_\mathrm{top} (G,\mathcal{U}|Y) and average sample complexity Asctop(G,UY)\mathrm{Asc}_\mathrm{top} (G,\mathcal{U}|Y). Given an invariant measure μ\mu of XX, we study the conditional local measure-theoretical intricacy Intμ±(G,UY)\mathrm{Int}_\mu^\pm(G,\mathcal{U}|Y) and average sample complexity Ascμ±(G,UY)\mathrm{Asc}_\mu^\pm(G,\mathcal{U}|Y). For any F{\o}lner sequence {Fn}nN\{F_n\}_{n\in\mathbb{N}}, we take {cSFn}SFn\{c^{F_n}_S\}_{S\subseteq F_n} to be the uniform system of coefficients. We establish the equivalence of Ascμ(G,UY)\mathrm{Asc}_\mu^-(G,\mathcal{U}|Y) and Ascμ+(G,UY)\mathrm{Asc}_\mu^+(G,\mathcal{U}|Y) when G=ZG=\mathbb{Z}. Furthermore, we verified that Ascμ(G,U)\mathrm{Asc}_\mu^-(G,\mathcal{U}) is equal to Ascμ+(G,U)\mathrm{Asc}_\mu^+(G,\mathcal{U}) in general case. Finally, we give a local variational principle of average sample complexity.

Keywords

Cite

@article{arxiv.2509.20738,
  title  = {Local intricacy and average sample complexity for amenable group actions},
  author = {J. Huang and Z. Xiao},
  journal= {arXiv preprint arXiv:2509.20738},
  year   = {2025}
}
R2 v1 2026-07-01T05:55:19.519Z