{ "id": "1604.06512", "version": "v1", "published": "2016-04-21T23:41:04.000Z", "updated": "2016-04-21T23:41:04.000Z", "title": "Ground States and Zero-Temperature Measures at the Boundary of Rotation Sets", "authors": [ "Tamara Kucherenko", "Christian Wolf" ], "comment": "26 pages", "categories": [ "math.DS" ], "abstract": "We consider a continuous dynamical system $f:X\\to X$ on a compact metric space $X$ equipped with an $m$-dimensional continuous potential $\\Phi=(\\phi_1,\\cdots,\\phi_m):X\\to \\bR^m$. We study the set of ground states $ GS(\\alpha)$ of the potential $\\alpha\\cdot \\Phi$ as a function of the direction vector $\\alpha\\in S^{m-1}$. %We also study the corresponding rotation vectors $\\rv(GS(\\alpha))$. We show that the structure of the ground state sets is naturally related to the geometry of the generalized rotation set of $\\Phi$. In particular, for each $\\alpha$ the set of rotation vectors of $ GS(\\alpha)$ forms a non-empty, compact and connected subset of a face $F_\\alpha(\\Phi)$ of the rotation set associated with $\\alpha$. Moreover, every ground state maximizes entropy among all invariant measures with rotation vectors in $F_\\alpha(\\Phi)$. We further establish the occurrence of several quite unexpected phenomena. Namely, we construct for any $m\\in\\bN$ examples with an exposed boundary point (i.e. $F_\\alpha(\\Phi)$ being a singleton) without a unique ground state. Further, we establish the possibility of a line segment face $F_\\alpha(\\Phi)$ with a unique but non-ergodic ground state. Finally, we establish the possibility that the set of rotation vectors of $GS(\\alpha)$ is a non-trivial line segment.", "revisions": [ { "version": "v1", "updated": "2016-04-21T23:41:04.000Z" } ], "analyses": { "subjects": [ "37D35", "37E45", "37B10", "37E45", "37L40" ], "keywords": [ "rotation set", "rotation vectors", "zero-temperature measures", "ground state maximizes entropy", "line segment face" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160406512K" } } }