{"693574":{"#nid":"693574","#data":{"type":"event","title":"PhD Defense by John Stavroulakis","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003EDate: Thursday, November 19th\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ETime: \u0026nbsp;11:00 am\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ERoom: Skiles 168\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ETitle:\u003C\/strong\u003E On the bow lemma and higher dimensional analogs.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECommittee\u003C\/strong\u003E: Igor Belegradek, Elena Braverman (University of Calgary), Mohammad Ghomi (advisor), Galyna Livshyts, Andrzej Swiech, Erik Verriest (ECE).\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAbstract:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EWe discuss the bow lemma or Schur comparison theorem, and in particular its higher dimensional analogs. We first investigate isoperimetry under upper and lower curvature bounds, including the Cartan-Hadamard conjecture. We then discuss Fenchel\u0027s theorem for CAT(0) spaces and its higher dimensional versions concerning tight (hyper)surfaces in Cartan-Hadamard manifolds. We also develop a rigidity mechanism for flat hypersurfaces in Alexandrov ambient spaces, which is applied to completely characterize surfaces which optimize total Gauss curvature in 3-folds with upper or lower curvature bounds.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ETeams link:\u003C\/strong\u003E \u003Ca href=\u0022https:\/\/teams.microsoft.com\/meet\/2172100941812051?p=0YimD0FGzxQfer6TrD\u0022\u003Ehttps:\/\/teams.microsoft.com\/meet\/2172100941812051?p=0YimD0FGzxQfer6TrD\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EOn the bow lemma and higher dimensional analogs.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"On the bow lemma and higher dimensional analogs."}],"uid":"27707","created_gmt":"2026-10-28 15:33:21","changed_gmt":"2026-10-28 15:34:34","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2026-11-19T11:00:00-05:00","event_time_end":"2026-11-19T13:00:00-05:00","event_time_end_last":"2026-11-19T13:00:00-05:00","gmt_time_start":"2026-11-19 16:00:00","gmt_time_end":"2026-11-19 18:00:00","gmt_time_end_last":"2026-11-19 18:00:00","rrule":null,"timezone":"America\/New_York"},"location":"Skiles 168","extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}