{ "id": "1903.08703", "version": "v1", "published": "2019-03-20T19:04:40.000Z", "updated": "2019-03-20T19:04:40.000Z", "title": "On Stable and Unstable Behaviours of Certain Rotation Segments", "authors": [ "Salvador Addas-Zanata", "Xiao-Chuan Liu" ], "comment": "5 figures", "categories": [ "math.DS" ], "abstract": "In this paper, we study non-wandering homeomorphisms of the two torus in the identity homotopy class, whose rotation sets are non-trivial line segments from $(0,0)$ to some totally irrational vector $(\\alpha,\\beta)$. We show this rotation set is in fact a non-generic phenomenon for any $C^r$ diffeomorphisms, with $r \\geq 1$. When such a rotation set does happen, assuming several natural conditions that are generically satisfied in the area-preserving world, we give a clearer description of its rotational behavior. More precisely, the dynamics admits bounded deviation along the direction $-(\\alpha,\\beta)$ in the lift, and the rotation set is locked inside an arbitrarily small cone with respect to small $C^0$-perturbations of the dynamics. On the other hand, for any non-wandering homeomorphism $f$ with this kind of rotation set, we also present a perturbation scheme in order for the rotation set to be eaten by rotation sets of nearby dynamics, in the sense that the later set has non-empty interior and contains the former one. These two flavors interplay and share the common goal of understanding the stability/instability properties of this kind of rotation set.", "revisions": [ { "version": "v1", "updated": "2019-03-20T19:04:40.000Z" } ], "analyses": { "keywords": [ "rotation set", "rotation segments", "unstable behaviours", "identity homotopy class", "non-wandering homeomorphism" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }