{ "id": "1901.00327", "version": "v1", "published": "2019-01-02T11:31:45.000Z", "updated": "2019-01-02T11:31:45.000Z", "title": "Asymptotic pairs in positive-entropy systems", "authors": [ "François Blanchard", "Bernard Host", "Sylvie Ruette" ], "comment": "Published in 2002", "journal": "Ergod. Th. & Dynam. Syst., 22, 671-686, 2002", "categories": [ "math.DS" ], "abstract": "We show that in a topological dynamical system $(X,T)$ of positive entropy there exist proper (positively) asymptotic pairs, that is, pairs $(x,y)$ such that $x\\not= y$ and $\\lim_{n\\to +\\infty} d(T^n x,T^n y)=0$. More precisely we consider a $T$-ergodic measure $\\mu$ of positive entropy and prove that the set of points that belong to a proper asymptotic pair is of measure $1$. When $T$ is invertible, the stable classes (i.e., the equivalence classes for the asymptotic equivalence) are not stable under $T^{-1}$: for $\\mu$-almost every $x$ there are uncountably many $y$ that are asymptotic with $x$ and such that $(x,y)$ is a Li-Yorke pair with respect to $T^{-1}$. We also show that asymptotic pairs are dense in the set of topological entropy pairs.", "revisions": [ { "version": "v1", "updated": "2019-01-02T11:31:45.000Z" } ], "analyses": { "subjects": [ "37B40", "37A35" ], "keywords": [ "positive-entropy systems", "positive entropy", "proper asymptotic pair", "asymptotic equivalence", "ergodic measure" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }