Persistent Non-Statistical Dynamics in One-Dimensional Maps

TL;DR

This paper classifies a family of one-dimensional maps with indifferent fixed points and singularities into three subfamilies, revealing diverse statistical behaviors including unique, delta, and non-statistical measures, with these behaviors being intermingled.

Contribution

It introduces a detailed classification of a new family of maps, showing the coexistence and approximation of different statistical behaviors within the same class.

Findings

Maps in one subfamily have a unique physical measure equivalent to Lebesgue.

Another subfamily's maps have physical measures as Dirac-delta at fixed points.

A third subfamily consists of non-statistical maps with no physical measure.

Abstract

We study a class $\widehat{\mathfrak{F}}$ of one-dimensional full branch maps introduced in [Doubly Intermittent Full Branch Maps with Critical Points and Singularities; D. Coates, S. Luzzatto, M. Mubarak, 2022], admitting two indifferent fixed points as well as critical points and/or singularities with unbounded derivative. We show that $\widehat{\mathfrak{F}}$ can be partitioned into 3 pairwise disjoint subfamilies $$\widehat{\mathfrak{F}} = \mathfrak{F} \cup \mathfrak{F}_\pm \cup \mathfrak{F}_*$$ such that all $g \in \mathfrak{F}$ have a unique physical measure equivalent to Lebesgue, all $g \in \mathfrak{F}_{\pm}$ have a physical measure which is a Dirac-$\delta$ measure on one of the (repelling) fixed points, and all $g \in \mathfrak{F}_{*}$ are non-statistical and in particular have no physical measure. Moreover we show that these subfamilies are intermingled: they can all be approximated by maps in the other subfamilies in natural topologies.