{ "id": "1303.0374", "version": "v1", "published": "2013-03-02T11:08:44.000Z", "updated": "2013-03-02T11:08:44.000Z", "title": "Minimal sets of fibre-preserving maps in graph bundles", "authors": [ "Sergii Kolyada", "Ľubomír Snoha", "Sergei Trofimchuk" ], "comment": "43 pages, 2 figures, 34 references, submitted", "categories": [ "math.DS" ], "abstract": "Topological structure of minimal sets is studied for a dynamical system $(E,F)$ given by a fibre-preserving, in general non-invertible, continuous selfmap $F$ of a graph bundle $E$. These systems include, as a very particular case, quasiperiodically forced circle homeomorphisms. Let $M$ be a minimal set of $F$ with full projection onto the base space $B$ of the bundle. We show that $M$ is nowhere dense or has nonempty interior depending on whether the set of so called endpoints of $M$ is dense in $M$ or is empty. If $M$ is nowhere dense, we prove that either a typical fibre of $M$ is a Cantor set, or there is a positive integer $N$ such that a typical fibre of $M$ has cardinality $N$. If $M$ has nonempty interior we prove that there is a positive integer $m$ such that a typical fibre of $M$, in fact even each fibre of $M$ over a \\emph{dense open} set $\\mathcal O \\subseteq B$, is a disjoint union of $m$ circles. Moreover, we show that each of the fibres of $M$ over $B\\setminus \\mathcal O$ is a union of circles properly containing a disjoint union of $m$ circles. Surprisingly, some of the circles in such \"non-typical\" fibres of $M$ may intersect. We also give sufficient conditions for $M$ to be a sub-bundle of $E$.", "revisions": [ { "version": "v1", "updated": "2013-03-02T11:08:44.000Z" } ], "analyses": { "subjects": [ "54H20", "37B05" ], "keywords": [ "minimal set", "graph bundle", "fibre-preserving maps", "typical fibre", "disjoint union" ], "note": { "typesetting": "TeX", "pages": 43, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1303.0374K" } } }