{ "id": "1803.04060", "version": "v1", "published": "2018-03-11T22:48:20.000Z", "updated": "2018-03-11T22:48:20.000Z", "title": "Automorphisms of the shift: Lyapunov exponents, entropy, and the dimension representation", "authors": [ "Scott Schmieding" ], "categories": [ "math.DS" ], "abstract": "Let $(X_{A},\\sigma_{A})$ be a shift of finite type and $\\text{Aut}(\\sigma_{A})$ its corresponding automorphism group. Associated to $\\phi \\in \\text{Aut}(\\sigma_{A})$ are certain Lyapunov exponents $\\alpha^{-}(\\phi), \\alpha^{+}(\\phi)$ which describe asymptotic behavior of the sequence of coding ranges of $\\phi^{n}$. We give lower bounds on $\\alpha^{-}(\\phi), \\alpha^{+}(\\phi)$ in terms of the spectral radius of the corresponding action of $\\phi$ on the dimension group associated to $(X_{A},\\sigma_{A})$. We also give lower bounds on the topological entropy $h_{top}(\\phi)$ in terms of a distinguished part of the spectrum of the action of $\\phi$ on the dimension group, but show that in general $h_{top}(\\phi)$ is not bounded below by the logarithm of the spectral radius of the action of $\\phi$ on the dimension group.", "revisions": [ { "version": "v1", "updated": "2018-03-11T22:48:20.000Z" } ], "analyses": { "keywords": [ "lyapunov exponents", "dimension representation", "dimension group", "lower bounds", "spectral radius" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }