{ "id": "2311.03709", "version": "v1", "published": "2023-11-07T04:22:38.000Z", "updated": "2023-11-07T04:22:38.000Z", "title": "Geodesic Envelopes in the Thurston Metric on Teichmuller space", "authors": [ "Assaf Bar-Natan" ], "comment": "26 pages, 7.5 figures. Comments and criticism welcome. This is a no-frills version of my PhD thesis :)", "categories": [ "math.GT" ], "abstract": "The Thurston metric on Teichmuller space, first introduced by W. P. Thurston is an asymmetric metric on Teichmuller space defined by $d_{Th}(X,Y) = \\frac12 log\\sup_{\\alpha} \\frac{l_{\\alpha}(Y)}{l_{\\alpha}(X)}$. This metric is geodesic, but geodesics are far from unique. In this thesis, we show that in the once-punctured torus, and in the four-times punctured sphere, geodesics stay a uniformly-bounded distance from each other. In other words, we show that the \\textbf{width} of the geodesic envelope, E(X,Y) between any pair of points $X,Y \\in T(S)$ (where $S = S_{1,1}$ or $S = S_{0,4}$) is bounded uniformly. To do this, we first identify extremal geodesics in Env(X,Y), and show that these correspond to stretch vectors, proving a conjecture of Huang, Ohshika and Papadopoulos. We then compute Fenchel-Nielsen twisting along these paths, and use these computations, along with estimates on earthquake path lengths, to prove the main theorem.", "revisions": [ { "version": "v1", "updated": "2023-11-07T04:22:38.000Z" } ], "analyses": { "keywords": [ "teichmuller space", "thurston metric", "geodesic envelope", "first identify extremal geodesics", "earthquake path lengths" ], "tags": [ "dissertation" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable" } } }