English

Broken family sensitivity in transitive systems

Dynamical Systems 2022-04-27 v1

Abstract

Let (X,T)(X,T) be a topological dynamical system, n2n\geq 2 and F\mathcal{F} be a Furstenberg family of subsets of Z+\mathbb{Z}_+. (X,T)(X,T) is called broken F\mathcal{F}-nn-sensitive if there exist δ>0\delta>0 and FFF\in\mathcal{F} such that for every opene (non-empty open) subset UU of XX and every lNl\in\mathbb{N}, there exist x1l,x2l,,xnlUx_1^l,x_2^l,\dotsc,x_n^l\in U and mlZ+m_l\in \mathbb{Z}_+ satisfying d(Tkxil,Tkxjl)>δ, 1i<jn,kml+F[1,l]d(T^k x_i^l, T^k x_j^l)> \delta,\ \forall 1\leq i<j\leq n, k\in m_l+ F\cap[1,l]. We investigate broken F\mathcal{F}-nn-sensitivity for the family of all piecewise syndetic subsets (Fps\mathcal{F}_{ps}), the family of all positive upper Banach density subsets (Fpubd\mathcal{F}_{pubd}) and the family of all infinite subsets (Finf\mathcal{F}_{inf}). We show that a transitive system (X,T)(X,T) is broken F\mathcal{F}-nn-sensitive for F=Fps or Fpubd\mathcal{F}=\mathcal{F}_{ps}\ \text{or}\ \mathcal{F}_{pubd} if and only if there exists an essential nn-sensitive tuple which is an F\mathcal{F}-recurrent point of (Xn,T(n))(X^n, T^{(n)}); is broken Finf\mathcal{F}_{inf}-nn-sensitive if and only if there exists an essential nn-sensitive tuple (x1,x2,,xn)(x_1,x_2,\dotsc,x_n) such that lim supkmin1i<jnd(Tkxi,Tkxj)>0\limsup_{k\to\infty}\min_{1\leq i<j\leq n}d(T^kx_i,T^kx_j)>0. We also obtain specific properties for them by analyzing the factor maps to their maximal equicontinuous factors. Furthermore, we show examples to distinguish different kinds of broken family sensitivity.

Cite

@article{arxiv.2203.13440,
  title  = {Broken family sensitivity in transitive systems},
  author = {Jian Li and Yini Yang},
  journal= {arXiv preprint arXiv:2203.13440},
  year   = {2022}
}

Comments

18 pages. J. Math. Anal. Appl. (2022), online

R2 v1 2026-06-24T10:25:29.141Z