2014/11/07 by Dominik Kwietniak, Piotr Oprocha, Kwietniak, Dominik +3 · 1 citation
Mathematics · #37A35 #37B05 #37B40 (primary) #37D45 (secondary) #Advanced Topology and Set Theory #Discrete mathematics #Dynamical Systems (math.DS) #Dynamical systems theory #Entropy (arrow of time) #Ergodic theory #Ergodicity #FOS: Mathematics #Invariant (physics) #Invariant measure #Mathematical Dynamics and Fractals #Mathematical physics #Mathematics #Physics #Property (philosophy) #Pure mathematics #Statistics #math.DS #msc:37A35 #msc:37B05 #msc:37B40 #msc:37D45
paper · pdf · doi:10.48550/arxiv.1411.1989
published in arXiv (Cornell University) (Cornell University)
arxiv created 2014/11/07 · openalex publication_date 2014/11/07 · arxiv updated 2014/11/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/08
We construct a family of shift spaces with almost specification and multiple measures of maximal entropy. This answers a question from Climenhaga and Thompson [Israel J. Math. 192 (2012), no. 2, 785--817]. Elaborating on our examples we also prove that some sufficient conditions for every subshift factor of a shift space to be intrinsically ergodic given by Climenhaga and Thompson are in some sense best possible, moreover, the weak specification property neither implies intrinsic ergodicity, nor follows from almost specification. We also construct a dynamical system with the weak specification property, which does not have the almost specification property. We prove that the minimal points are dense in the support of any invariant measure of a system with the almost specification property. Furthermore, if a system with almost specification has an invariant measure with non-trivial support, then it also has uniform positive entropy over the support of any invariant measure and can not be minimal.