{ "id": "1801.05879", "version": "v1", "published": "2018-01-17T22:38:31.000Z", "updated": "2018-01-17T22:38:31.000Z", "title": "Analysis of the Vanishing Moment Method and its Finite Element Approximations for Second-order Linear Elliptic PDEs in Non-divergence Form", "authors": [ "Xiaobing Feng", "Thomas Lewis", "Stefan Schnake" ], "categories": [ "math.NA" ], "abstract": "This paper is concerned with continuous and discrete approximations of $W^{2,p}$ strong solutions of second-order linear elliptic partial differential equations (PDEs) in non-divergence form. The continuous approximation of these equations is achieved through the Vanishing Moment Method (VMM) which adds a small biharmonic term to the PDE. The structure of the new fourth-order PDE is a natural fit for Galerkin-type methods unlike the original second order equation since the highest order term is in divergence form. The well-posedness of the weak form of the perturbed fourth order equation is shown as well as error estimates for approximating the strong solution of the original second-order PDE. A $C^1$ finite element method is then proposed for the fourth order equation, and its existence and uniqueness of solutions as well as optimal error estimates in the $H^2$ norm are shown. Lastly, numerical tests are given to show the validity of the method.", "revisions": [ { "version": "v1", "updated": "2018-01-17T22:38:31.000Z" } ], "analyses": { "subjects": [ "65N12", "65N15", "65N30" ], "keywords": [ "second-order linear elliptic pdes", "vanishing moment method", "finite element approximations", "non-divergence form", "elliptic partial differential equations" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }