{ "id": "1906.08700", "version": "v1", "published": "2019-06-20T15:42:47.000Z", "updated": "2019-06-20T15:42:47.000Z", "title": "On quasi-reversibility solutions to the Cauchy problem for the Laplace equation: regularity and error estimates", "authors": [ "Laurent Bourgeois", "Lucas Chesnel" ], "categories": [ "math.AP", "cs.NA", "math.NA" ], "abstract": "We are interested in the classical ill-posed Cauchy problem for the Laplace equation. One method to approximate the solution associated with compatible data consists in considering a family of regularized well-posed problems depending on a small parameter $\\varepsilon>0$. In this context, in order to prove convergence of finite elements methods, it is necessary to get regularity results of the solutions to these regularized problems which hold uniformly in $\\varepsilon$. In the present work, we obtain these results in smooth domains and in 2D polygonal geometries. In presence of corners, due the particular structure of the regularized problems, classical techniques \\`a la Grisvard do not work and instead, we apply the Kondratiev approach. We describe the procedure in detail to keep track of the dependence in $\\varepsilon$ in all the estimates. The main originality of this study lies in the fact that the limit problem is ill-posed in any framework.", "revisions": [ { "version": "v1", "updated": "2019-06-20T15:42:47.000Z" } ], "analyses": { "keywords": [ "laplace equation", "error estimates", "quasi-reversibility solutions", "finite elements methods", "regularized problems" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }