{ "id": "1701.07415", "version": "v1", "published": "2017-01-25T18:20:29.000Z", "updated": "2017-01-25T18:20:29.000Z", "title": "On the numerical approximation of $p$-Biharmonic and $\\infty$-Biharmonic functions", "authors": [ "Nikos Katzourakis", "Tristan Pryer" ], "comment": "21 pages, 5 figures", "categories": [ "math.NA", "math.AP" ], "abstract": "In [KP16] (https://arxiv.org/pdf/1605.07880) the authors introduced a second order variational problem in $L^{\\infty}$. The associated equation, coined the $\\infty$-Bilaplacian, is a \\emph{third order} fully nonlinear PDE given by $\\Delta^2_\\infty u\\, := (\\Delta u)^3 | D (\\Delta u) |^2 = 0.$ In this work we build a numerical method aimed at quantifying the nature of solutions to this problem which we call $\\infty$-Biharmonic functions. For fixed $p$ we design a mixed finite element scheme for the pre-limiting equation, the $p$-Bilaplacian $\\Delta^2_p u\\, := \\Delta(| \\Delta u |^{p-2} \\Delta u) = 0.$ We prove convergence of the numerical solution to the weak solution of $\\Delta^2_p u = 0$ and show that we are able to pass to the limit $p\\to\\infty$. We perform various tests aimed at understanding the nature of solutions of $\\Delta^2_\\infty u$ and in 1-$d$ we prove convergence of our discretisation to an appropriate weak solution concept of this problem, that of $\\mathcal D$-solutions.", "revisions": [ { "version": "v1", "updated": "2017-01-25T18:20:29.000Z" } ], "analyses": { "keywords": [ "biharmonic functions", "numerical approximation", "appropriate weak solution concept", "second order variational problem", "mixed finite element scheme" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable" } } }