{ "id": "1608.01035", "version": "v1", "published": "2016-08-03T00:23:37.000Z", "updated": "2016-08-03T00:23:37.000Z", "title": "Wavenumber-explicit analysis for the Helmholtz $h$-BEM: error estimates and iteration counts for the Dirichlet problem", "authors": [ "Jeffrey Galkowski", "Eike H. Müller", "Euan A. Spence" ], "categories": [ "math.NA", "math.AP" ], "abstract": "We consider solving the exterior Dirichlet problem for the Helmholtz equation with the $h$-version of the boundary element method using the standard second-kind combined-field integral equations. We sharpen previously-existing results on how $h$ must decrease with $k$ to maintain $k$-independent quasi-optimality of the Galerkin solutions, and we prove new bounds on how the number of GMRES iterations must grow with $k$ in order to have the error in the iterative solution bounded independently of $k$. Despite the fact that all the integral-operator bounds used in these arguments are sharp in their $k$-dependence, numerical experiments demonstrate that although the bounds on $h$ and the number of iterations are sufficient, they are not necessary for many geometries. We prove these results by proving new, sharp bounds on norms of the Helmholtz single- and double-layer boundary integral operators as mappings from $L^2(\\Gamma)\\rightarrow H^1(\\Gamma)$ (where $\\Gamma$ is the boundary of the obstacle), and then using these in conjunction with existing results. The new $L^2(\\Gamma)\\rightarrow H^1(\\Gamma)$ bounds are obtained using estimates on the restriction to the boundary of eigenfunctions of the Laplacian, building on recent work by the first author and collaborators.", "revisions": [ { "version": "v1", "updated": "2016-08-03T00:23:37.000Z" } ], "analyses": { "subjects": [ "35J05", "65F10", "65N22", "65N38", "65R20", "78A45" ], "keywords": [ "dirichlet problem", "error estimates", "iteration counts", "wavenumber-explicit analysis", "standard second-kind combined-field integral equations" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }