{ "id": "1803.04082", "version": "v1", "published": "2018-03-12T01:19:40.000Z", "updated": "2018-03-12T01:19:40.000Z", "title": "Real entropy rigidity under quasi-conformal deformations", "authors": [ "Khashayar Filom" ], "comment": "44 pages, 1 figure", "categories": [ "math.DS" ], "abstract": "We set up a real entropy function $h_\\Bbb{R}$ on the space $\\mathcal{M}'_d$ of M\\\"obius conjugacy classes of real rational maps of degree $d$ by assigning to each class the real entropy of a representative $f\\in\\Bbb{R}(z)$; namely, the topological entropy of its restriction $f\\restriction_{\\hat{\\Bbb{R}}}$ to the real circle. We prove a structure theorem for the real Julia set $\\mathcal{J}_\\Bbb{R}(f):=\\mathcal{J}(f)\\cap\\hat{\\Bbb{R}}$ that will be utilized to establish a rigidity result stating that $h_\\Bbb{R}$ is locally constant on the subspace determined by real maps which are quasi-conformally conjugate to $f$. We also compare the real locus $\\mathcal{M}_d(\\Bbb{R})$ of the moduli space $\\mathcal{M}_d(\\Bbb{C})$ of degree $d$ rational maps to the locus $\\mathcal{M}'_d$ of classes with a real representative, and we characterize maps of maximal real entropy.", "revisions": [ { "version": "v1", "updated": "2018-03-12T01:19:40.000Z" } ], "analyses": { "subjects": [ "37B40", "37E05", "37E10", "37F10", "37F30", "37P45" ], "keywords": [ "real entropy rigidity", "quasi-conformal deformations", "maximal real entropy", "real julia set", "real entropy function" ], "note": { "typesetting": "TeX", "pages": 44, "language": "en", "license": "arXiv", "status": "editable" } } }