{ "id": "1506.06576", "version": "v1", "published": "2015-06-22T12:52:40.000Z", "updated": "2015-06-22T12:52:40.000Z", "title": "Derivatives of length functions and shearing coordinates on teichm{ΓΌ}ller spaces", "authors": [ "Matthieu Gendulphe" ], "categories": [ "math.GT" ], "abstract": "Let $S$ be a closed oriented surface of genus at least $2$, and denote by $\\teich(S)$ its Teichm\\\"uller space. For any isotopy class of closed curves $\\g$, we compute the first three derivatives of the length function $\\ell\\_\\g:\\teich(S)\\rightarrow\\R\\_+$ in the shearing coordinates associated to a maximal geodesic lamination $\\l$. We show that if $\\g$ intersects any leaf of $\\l$, then the Hessian of $\\ell\\_\\g$ is positive-definite. We extend this result to length functions of measured laminations. We also provide a method to compute higher derivatives of length functions of geodesics. We use Bonahon's theory of transverse H\\\"older distributions and shearing coordinates.", "revisions": [ { "version": "v1", "updated": "2015-06-22T12:52:40.000Z" } ], "analyses": { "keywords": [ "length function", "shearing coordinates", "ller spaces", "maximal geodesic lamination", "isotopy class" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150606576G" } } }