{"title":"Remetrizing dynamical systems to control distances of points in time","authors":"Krzysztof Gołębiowski","doi":"10.1016/j.topol.2025.109419","DOIUrl":null,"url":null,"abstract":"<div><div>Main aim of this article is to prove that for any continuous function <span><math><mi>f</mi><mo>:</mo><mi>X</mi><mo>→</mo><mi>X</mi></math></span>, where <em>X</em> is metrizable (or, more generally, for any family <span><math><mi>F</mi></math></span> of such functions, with one extra condition), there exists a compatible metric <em>d</em> on <em>X</em> such that the nth iteration of <em>f</em> (more generally, composition of any <em>n</em> functions from <span><math><mi>F</mi></math></span>) is Lipschitz with constant <span><math><msub><mrow><mi>a</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span> where <span><math><msubsup><mrow><mo>(</mo><msub><mrow><mi>a</mi></mrow><mrow><mi>n</mi></mrow></msub><mo>)</mo></mrow><mrow><mi>n</mi><mo>=</mo><mn>1</mn></mrow><mrow><mo>∞</mo></mrow></msubsup></math></span> is an arbitrarily fixed sequence of real numbers such that <span><math><mn>1</mn><mo><</mo><msub><mrow><mi>a</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span> and <span><math><munder><mi>lim</mi><mrow><mi>n</mi><mo>→</mo><mo>+</mo><mo>∞</mo></mrow></munder><mo></mo><msub><mrow><mi>a</mi></mrow><mrow><mi>n</mi></mrow></msub><mo>=</mo><mo>+</mo><mo>∞</mo></math></span>. In particular, any dynamical system can be remetrized in order to significantly control the distance between points by their initial distance.</div></div>","PeriodicalId":51201,"journal":{"name":"Topology and its Applications","volume":"370 ","pages":"Article 109419"},"PeriodicalIF":0.6000,"publicationDate":"2025-05-06","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/S0166864125002172","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Main aim of this article is to prove that for any continuous function , where X is metrizable (or, more generally, for any family of such functions, with one extra condition), there exists a compatible metric d on X such that the nth iteration of f (more generally, composition of any n functions from ) is Lipschitz with constant where is an arbitrarily fixed sequence of real numbers such that and . In particular, any dynamical system can be remetrized in order to significantly control the distance between points by their initial distance.
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.