{"id":374,"date":"2016-03-31T02:23:31","date_gmt":"2016-03-31T02:23:31","guid":{"rendered":"http:\/\/pages.charlotte.edu\/colloquium\/?p=374"},"modified":"2016-03-31T02:25:03","modified_gmt":"2016-03-31T02:25:03","slug":"friday-april-1st-at-1100am-math-conference-room","status":"publish","type":"post","link":"https:\/\/pages.charlotte.edu\/colloquium\/blog\/2016\/03\/31\/friday-april-1st-at-1100am-math-conference-room\/","title":{"rendered":"Friday April 1st, at 11:00AM  Math Conference room"},"content":{"rendered":"<table>\n<tbody>\n<tr>\n<td><a href=\"http:\/\/homepages.warwick.ac.uk\/staff\/C.Ortner\/\">Christoph Ortner<\/a>, Mathematics Institute, University of Warwick<\/td>\n<\/tr>\n<tr>\n<td>Title: The Dimer Method for Saddle Point Computations<\/td>\n<\/tr>\n<tr>\n<td>\n<p>Abstract:The dimer method is a simple hessian-free algorithm for computing index-1 saddles. I will review this algorithm and describe some improvements to its efficiency, in particular adding preconditioning capabilities and line-search based on a local merit function. I will demonstrate the efficiency of the new variant on a range of applications from academic toy problems, an atomistic problem and a PDE problem.<\/p>\n<p>Despite these new improvements, we can currently give no global convergence guarantee. Indeed, we can construct counterexamples to global convergence. I will conclude my talk by explaining some of the difficulties we encountered and posing a challenge for the optimisation community.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Christoph Ortner, Mathematics Institute, University of Warwick Title: The Dimer Method for Saddle Point Computations Abstract:The dimer method is a simple hessian-free algorithm for computing index-1 saddles. I will review this algorithm and describe some improvements to its efficiency, in particular adding preconditioning capabilities and line-search based on a local merit function. I will demonstrate [&hellip;]<\/p>\n","protected":false},"author":333,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[1],"tags":[],"class_list":["post-374","post","type-post","status-publish","format-standard","hentry","category-spring-2022"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p3kCtT-62","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/posts\/374","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/users\/333"}],"replies":[{"embeddable":true,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/comments?post=374"}],"version-history":[{"count":2,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/posts\/374\/revisions"}],"predecessor-version":[{"id":376,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/posts\/374\/revisions\/376"}],"wp:attachment":[{"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/media?parent=374"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/categories?post=374"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pages.charlotte.edu\/colloquium\/wp-json\/wp\/v2\/tags?post=374"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}