

{"id":4,"date":"2011-12-08T11:55:34","date_gmt":"2011-12-08T11:55:34","guid":{"rendered":"http:\/\/project.inria.fr\/template1\/?page_id=4"},"modified":"2025-10-06T09:53:57","modified_gmt":"2025-10-06T07:53:57","slug":"home","status":"publish","type":"page","link":"https:\/\/project.inria.fr\/ranpdes\/","title":{"rendered":"Introduction"},"content":{"rendered":"<p><\/p>\n<p>PDEs (partial differential equations) are ubiquitous in the modelling of real-world problems. The exact solutions of these equations can never be found in practice, so that numerical schemes (mathematical algorithms executed on a computer) are required for their approximation. The ultimate goal of the RANPDEs project is to design algorithms that allow to compute a numerical approximation with <strong>error<\/strong> below some <strong>desired tolerance<\/strong> at the expense of <strong>minimal computational cost<\/strong>. To this end, we first accurately quantify the overall error and identify its different components:<\/p>\n<ul>\n<li>discretization error from the finite element method,<\/li>\n<li>linearization error from the iterative linearization scheme (fixed-point, Newton,&#8230;),<\/li>\n<li>algebraic error from the iterative algebraic solver,<\/li>\n<li>&#8230;<\/li>\n<\/ul>\n<p>We then apply <strong>adaptivity<\/strong> in a broad sense:<\/p>\n<ul>\n<li><strong>mesh refinement<\/strong>,<\/li>\n<li><strong>polynomial degree adjustment<\/strong>,<\/li>\n<li><strong>stopping criteria <\/strong>for the iterative solvers,<\/li>\n<li>&#8230;<\/li>\n<\/ul>\n<p>Robust <strong>a posteriori error estimators<\/strong> are our main tool. We focus on proofs of <strong>contraction<\/strong> and <strong>optimality<\/strong> with respect to the total cost of the numerical simulation, for several classes of important <strong>model nonlinear partial differential equations<\/strong>. Numerical experiments illustrate all the theoretical developments.<\/p>\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>PDEs (partial differential equations) are ubiquitous in the modelling of real-world problems. The exact solutions of these equations can never be found in practice, so that numerical schemes (mathematical algorithms executed on a computer) are required for their approximation. The ultimate goal of the RANPDEs project is to design algorithms\u2026<\/p>\n<p> <a class=\"continue-reading-link\" href=\"https:\/\/project.inria.fr\/ranpdes\/\"><span>Continue reading<\/span><i class=\"crycon-right-dir\"><\/i><\/a> <\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-4","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/project.inria.fr\/ranpdes\/wp-json\/wp\/v2\/pages\/4","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/project.inria.fr\/ranpdes\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/project.inria.fr\/ranpdes\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/project.inria.fr\/ranpdes\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/project.inria.fr\/ranpdes\/wp-json\/wp\/v2\/comments?post=4"}],"version-history":[{"count":11,"href":"https:\/\/project.inria.fr\/ranpdes\/wp-json\/wp\/v2\/pages\/4\/revisions"}],"predecessor-version":[{"id":98,"href":"https:\/\/project.inria.fr\/ranpdes\/wp-json\/wp\/v2\/pages\/4\/revisions\/98"}],"wp:attachment":[{"href":"https:\/\/project.inria.fr\/ranpdes\/wp-json\/wp\/v2\/media?parent=4"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}