{ "id": "2406.09276", "version": "v1", "published": "2024-06-13T16:14:34.000Z", "updated": "2024-06-13T16:14:34.000Z", "title": "Multigrid preconditioning for discontinuous Galerkin discretizations of an elliptic optimal control problem with a convection-dominated state equation", "authors": [ "Sijing Liu", "Valeria Simoncini" ], "categories": [ "math.NA", "cs.NA" ], "abstract": "We consider discontinuous Galerkin methods for an elliptic distributed optimal control problem constrained by a convection-dominated problem. We prove global optimal convergence rates using an inf-sup condition, with the diffusion parameter $\\varepsilon$ and regularization parameter $\\beta$ explicitly tracked. We then propose a multilevel preconditioner based on downwind ordering to solve the discretized system. The preconditioner only requires two approximate solves of single convection-dominated equations using multigrid methods. Moreover, for the strongly convection-dominated case, only two sweeps of block Gauss-Seidel iterations are needed. We also derive a simple bound indicating the role played by the multigrid preconditioner. Numerical results are shown to support our findings.", "revisions": [ { "version": "v1", "updated": "2024-06-13T16:14:34.000Z" } ], "analyses": { "subjects": [ "49J20", "49M41", "65N30", "65N55" ], "keywords": [ "elliptic optimal control problem", "discontinuous galerkin discretizations", "convection-dominated state equation", "multigrid preconditioning", "elliptic distributed optimal control problem" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }