English

Critically Finite Random Maps of an Interval

Dynamical Systems 2021-07-16 v1

Abstract

We consider random multimodal C3C^3 maps with negative Schwarzian derivative, defined on a finite union of closed intervals in [0,1][0,1], onto the interval [0,1][0,1] with the base space Ω\Omega and a base invertible ergodic map θ:ΩΩ\theta:\Omega\to\Omega preserving a probability measure mm on Ω\Omega. We denote the corresponding skew product map by TT and call it a critically finite random map of an interval. We prove that there exists a subset AA(T)AA(T) of [0,1][0,1] with the following properties: (1) For each tAA(T)t\in AA(T) a tt-conformal random measure νt\nu_t exists. We denote by λt,νt,ω\lambda_{t,\nu_t,\omega} the corresponding generalized eigenvalues of the corresponding dual operators Lt,ω\mathcal{L}_{t,\omega}^*, ωΩ\omega\in\Omega. (2) Given t0t\ge 0 any two tt-conformal random measures are equivalent. (3) The expected topological pressure of the parameter tt: EP(t):=Ωlogλt,ν,ωdm(ω)\mathcal{E}P(t):=\int_{\Omega}\log\lambda_{t,\nu,\omega}dm(\omega) is independent of the choice of a tt-conformal random measure ν\nu. (4) The function AA(T)tEP(t)R AA(T)\ni t\longmapsto \mathcal{E}P(t)\in\mathbb R is monotone decreasing and Lipschitz continuous. (5) With bTb_T being defined as the supremum of such parameters tAA(T)t\in AA(T) that EP(t)0\mathcal{E}P(t)\ge 0, it holds that EP(bT)=0   and   [0,bT]Int(AA(T)). \mathcal{E}P(b_T)=0 \ \ \ {\rm and} \ \ \ [0,b_T]\subset \text{Int}(AA(T)). (6) HD(Jω(T))=bT\text{HD}(\mathcal{J}_\omega(T))=b_T for mm-a.e ωΩ\omega\in\Omega, where Jω(T)\mathcal{J}_\omega(T), ωΩ\omega\in\Omega, form the random closed set generated by the skew product map TT. (7) bT=1b_T=1 if and only if ΔGΔ=[0,1]\bigcup_{\Delta\in \mathcal{G}}\Delta=[0,1], and then Jω(T)=[0,1]\mathcal{J}_\omega(T)=[0,1] for all ωΩ\omega\in\Omega.

Keywords

Cite

@article{arxiv.1810.05013,
  title  = {Critically Finite Random Maps of an Interval},
  author = {Jason Atnip and Mariusz Urbański},
  journal= {arXiv preprint arXiv:1810.05013},
  year   = {2021}
}
R2 v1 2026-06-23T04:36:18.339Z