{ "id": "1306.6355", "version": "v1", "published": "2013-06-26T20:34:37.000Z", "updated": "2013-06-26T20:34:37.000Z", "title": "The Lusin theorem and horizontal graphs in the Heisenberg group", "authors": [ "Piotr Hajlasz", "Jacob Mirra" ], "categories": [ "math.FA", "math.AP" ], "abstract": "In this paper we prove that every collection of measurable functions $f_\\alpha$, $|\\alpha|=m$ coincides a.e. with $m$th order derivatives of a function $g\\in C^{m-1}$ whose derivatives of order $m-1$ may have any modulus of continuity weaker than that of a Lipschitz function. This is a stronger version of earlier results of Lusin, Moonens-Pfeffer and Francos. As an application we construct surfaces in the Heisenberg group with tangent spaces being horizontal a.e.", "revisions": [ { "version": "v1", "updated": "2013-06-26T20:34:37.000Z" } ], "analyses": { "subjects": [ "46E35", "46E30" ], "keywords": [ "heisenberg group", "horizontal graphs", "lusin theorem", "th order derivatives", "tangent spaces" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1306.6355H" } } }