{"title":"Density of distributional chaos in non-autonomous systems","authors":"Francisco Balibrea , Lenka Rucká","doi":"10.1016/j.topol.2026.109735","DOIUrl":null,"url":null,"abstract":"<div><div>In this paper we are interested in two open problems concerning distributional chaos in non-autonomous discrete dynamical systems as stated in <span><span>[4]</span></span> and <span><span>[18]</span></span>. As a negative answer to the first problem, we show that positive topological entropy of a pointwise convergent non-autonomous system (as well as distributional chaos of this system) does not imply distributional chaos of its limit map. This disproves a conjecture in <span><span>[18]</span></span>. In the second open problem it is wondered if the distributional chaos is a generic property of pointwise convergent non-autonomous systems. We show that the answer is negative for convergent systems on the Cantor set. On the other hand we prove, that distributionally chaotic systems form a dense, but not open (nor closed) set in the space of non-autonomous convergent systems on the interval, independent of the metric we use.</div></div>","PeriodicalId":51201,"journal":{"name":"Topology and its Applications","volume":"380 ","pages":"Article 109735"},"PeriodicalIF":0.5000,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Topology and its Applications","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0166864126000258","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/1/16 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
In this paper we are interested in two open problems concerning distributional chaos in non-autonomous discrete dynamical systems as stated in [4] and [18]. As a negative answer to the first problem, we show that positive topological entropy of a pointwise convergent non-autonomous system (as well as distributional chaos of this system) does not imply distributional chaos of its limit map. This disproves a conjecture in [18]. In the second open problem it is wondered if the distributional chaos is a generic property of pointwise convergent non-autonomous systems. We show that the answer is negative for convergent systems on the Cantor set. On the other hand we prove, that distributionally chaotic systems form a dense, but not open (nor closed) set in the space of non-autonomous convergent systems on the interval, independent of the metric we use.
期刊介绍:
Topology and its Applications is primarily concerned with publishing original research papers of moderate length. However, a limited number of carefully selected survey or expository papers are also included. The mathematical focus of the journal is that suggested by the title: Research in Topology. It is felt that it is inadvisable to attempt a definitive description of topology as understood for this journal. Certainly the subject includes the algebraic, general, geometric, and set-theoretic facets of topology as well as areas of interactions between topology and other mathematical disciplines, e.g. topological algebra, topological dynamics, functional analysis, category theory. Since the roles of various aspects of topology continue to change, the non-specific delineation of topics serves to reflect the current state of research in topology.
At regular intervals, the journal publishes a section entitled Open Problems in Topology, edited by J. van Mill and G.M. Reed. This is a status report on the 1100 problems listed in the book of the same name published by North-Holland in 1990, edited by van Mill and Reed.