{ "id": "1704.04492", "version": "v1", "published": "2017-04-14T17:47:20.000Z", "updated": "2017-04-14T17:47:20.000Z", "title": "Rigidity and flatness of the image of certain classes of mappings having tangential Laplacian", "authors": [ "Hussien Abugirda", "Birzhan Ayanbayev", "Nikos Katzourakis" ], "comment": "15 pages, 2 figures", "categories": [ "math.AP" ], "abstract": "In this paper we consider the PDE system of vanishing normal projection of the Laplacian for $C^2$ maps $u : \\mathbb{R}^n \\supseteq \\Omega \\longrightarrow \\mathbb{R}^N$: \\[ [\\![\\mathrm{D} u]\\!]^\\bot \\Delta u = 0 \\ \\, \\text{ in }\\Omega. \\] This system has discontinuous coefficients and geometrically expresses the fact that the Laplacian is a vector field tangential to the image of the mapping. It arises as a constituent component of the $p$-Laplace system for all $p\\in [2,\\infty]$. For $p=\\infty$, the $\\infty$-Laplace system is the archetypal equation describing extrema of supremal functionals in vectorial Calculus of Variations in $L^\\infty$. Herein we show that the image of a solution $u$ is piecewise affine if either the rank of $\\mathrm{D} u$ is equal to one or $n=2$ and $u$ has additively separated form. As a consequence we obtain corresponding flatness results for $p$-Harmonic maps, $p\\in [2,\\infty]$.", "revisions": [ { "version": "v1", "updated": "2017-04-14T17:47:20.000Z" } ], "analyses": { "keywords": [ "tangential laplacian", "laplace system", "vector field tangential", "vectorial calculus", "vanishing normal projection" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }