{ "id": "1610.01786", "version": "v1", "published": "2016-10-06T09:26:38.000Z", "updated": "2016-10-06T09:26:38.000Z", "title": "Discrete $p$-robust $\\mathbf{H}(\\mathrm{div})$-liftings and a posteriori estimates for elliptic problems with $H^{-1}$ source terms", "authors": [ "Alexandre Ern", "Iain Smears", "Martin VohralĂ­k" ], "categories": [ "math.NA" ], "abstract": "We establish the existence of liftings into discrete subspaces of $\\mathbf{H}(\\mathrm{div})$ of piecewise polynomial data on locally refined simplicial partitions of polygonal/polyhedral domains. Our liftings are robust with respect to the polynomial degree. This result has important applications in the a posteriori error analysis of parabolic problems, where it permits the removal of so-called transition conditions that link two consecutive meshes. It can also be used in a the posteriori error analysis of elliptic problems, where it allows the treatment of meshes with arbitrary numbers of hanging nodes between elements. We present a constructive proof based on the a posteriori error analysis of an auxiliary elliptic problem with $H^{-1}$ source terms, thereby yielding results of independent interest. In particular, for such problems, we obtain guaranteed upper bounds on the error along with polynomial-degree robust local efficiency of the estimators.", "revisions": [ { "version": "v1", "updated": "2016-10-06T09:26:38.000Z" } ], "analyses": { "subjects": [ "65N30" ], "keywords": [ "source terms", "posteriori error analysis", "posteriori estimates", "polynomial-degree robust local efficiency", "auxiliary elliptic problem" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }