{ "id": "1611.05936", "version": "v1", "published": "2016-11-18T00:45:24.000Z", "updated": "2016-11-18T00:45:24.000Z", "title": "A Pointwise Characterisation of the PDE System of Vectorial Calculus of Variations in $L^\\infty$", "authors": [ "Birzhan Ayanbayev", "Nikos Katzourakis" ], "comment": "13 pages", "categories": [ "math.AP" ], "abstract": "Let $n,N\\in \\mathbb{N}$ with $\\Omega \\subseteq \\mathbb{R}^n$ open. Given $H \\in C^2(\\Omega \\times \\mathbb{R}^N\\times \\mathbb{R}^{Nn}),$ we consider the functional \\[ \\tag{1} \\label{1} E_\\infty (u,\\mathcal{O})\\, :=\\, \\underset{\\mathcal{O}}{\\mathrm{ess}\\,\\sup}\\, H (\\cdot,u,\\mathrm{D} u) ,\\ \\ \\ u\\in W^{1,\\infty}_\\text{loc}(\\Omega,\\mathbb{R}^N),\\ \\ \\ \\mathcal{O} \\Subset \\Omega. \\] The associated PDE system which plays the role of Euler-Lagrange equations in $L^\\infty$ is \\[ \\label{2} \\tag{2} \\left\\{ \\begin{array}{r} H_{P}(\\cdot, u, \\mathrm{D}u)\\, \\mathrm{D} \\big(H(\\cdot, u, \\mathrm{D} u)\\big) \\, = \\, 0, \\ \\ \\ H(\\cdot, u, \\mathrm{D} u) \\, [\\![H_{P}(\\cdot, u, \\mathrm{D} u)]\\!]^\\bot \\Big(\\mathrm{Div}\\big(H_{P}(\\cdot, u, \\mathrm{D} u)\\big)- H_{\\eta}(\\cdot, u, \\mathrm{D} u)\\Big)\\, =\\, 0, \\end{array} \\right. \\] where $[\\![A]\\!]^\\bot := \\mathrm{Proj}_{R(A)^\\bot}$. Herein we establish that generalised solutions to \\eqref{2} can be characterised as local minimisers of \\eqref{1} for appropriate classes of affine variations of the energy. Generalised solutions to \\eqref{2} are understood as $\\mathcal{D}$-solutions, a general framework recently introduced by one of the authors.", "revisions": [ { "version": "v1", "updated": "2016-11-18T00:45:24.000Z" } ], "analyses": { "keywords": [ "vectorial calculus", "pointwise characterisation", "generalised solutions", "euler-lagrange equations", "appropriate classes" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }