{ "133530-21873203": { "datetime_modified":"20250307T100152", "datetime_start":"20250320T110000", "datetime_end":"20250320T130000", "has_end_time":1, "date_start":"2025-03-20", "date_end":"2025-03-20", "time_start":"11:00:00", "time_end":"13:00:00", "time_zone":"America\/Detroit", "event_title":"Dissertation Defense: Thurston Theory for a Family of Chebyshev Polynomials and Cosine Maps", "occurrence_title":"", "combined_title":"Dissertation Defense: Thurston Theory for a Family of Chebyshev Polynomials and Cosine Maps: Schinella D'Souza", "event_subtitle":"Schinella D'Souza", "event_type":"Presentation", "event_type_id":"16", "description":"Abstract:\r\n\r\nA cornerstone of complex dynamics is William Thurston's topological characterization of rational functions, which provides a way to understand when topological objects are realized as geometric objects. These topological objects are finite degree branched maps of the topological sphere S^2 and the geometric objects are holomorphic maps of the Riemann sphere \\hat{\\mathbb{C}}, both of which are postcritically finite (i.e., the set of points in the orbit of the critical points is finite). We apply this framework to study a one-parameter family of modified Chebyshev polynomials from a dynamical and nondynamical perspective. Our interest in this family comes from the property that it approximates a one-parameter cosine family. This ties into a natural question that has arisen: can Thurston's characterization be extended to entire transcendental maps? In this setting, the analog of postcritically finite maps are postsingularly finite maps on the complex plane \\mathbb{C}, but for our cosine family, these notions coincide. Our work is based on the major breakthrough of Hubbard, Schleicher, and Shishikura in their characterization of exponential maps. We adapt their techniques for our cosine family to prove a partial characterization of postsingularly finite topological cosine maps.", "occurrence_notes":null, "guid":"133530-21873203@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/133530", "building_id":"1000166", "building_name":"East Hall", "campus_maps_id":"53", "room":"B860G", "location_name":"East Hall", "has_livestream":1, "livestream_type":"zoom", "livetream_require_login":0, "livestream_id":"93362792600", "livestream_password":"JCFDU5OTTXUB2NCXVBHWKNV169DJAV.1", "livestream_link":"https:\/\/umich.zoom.us\/j\/93362792600", "cost":"", "tags":["Mathematics","Graduate Students","Graduate","Dissertation"], "website":"", "sponsors":[ { "group_name":"Dissertation Defense - Department of Mathematics", "group_id":"4889", "website":"" }, { "group_name":"Department of Mathematics", "group_id":"3791", "website":"" } ], "image_url":"https:\/\/events.umich.edu\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "styled_images":{ "event_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_thumb\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "event_large":"https:\/\/events.umich.edu\/media\/cache\/event_large\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "event_large_2x":"https:\/\/events.umich.edu\/media\/cache\/event_large_2x\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "event_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/event_large_lightbox\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "group_thumb":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_thumb\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "group_thumb_square":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_thumb_square\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "group_large":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_large\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "group_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_large_lightbox\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "event_large_crop":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_large_crop\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "event_list":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_list\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "event_list_2x":"https:\/\/events.umich.edu\/media\/cache\/event_list_2x\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "event_grid":"https:\/\/events.umich.edu\/media\/cache\/event_grid\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "event_grid_2x":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_grid_2x\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "event_feature_large":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_feature_large\/media\/attachments\/2025\/03\/event_133530_original-2.jpg", "event_feature_thumb":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_feature_thumb\/media\/attachments\/2025\/03\/event_133530_original-2.jpg" }, "occurrence_count":1, "first_occurrence":21873203 } , "132833-21871937": { "datetime_modified":"20250227T100812", "datetime_start":"20250320T110000", "datetime_end":"20250320T120000", "has_end_time":1, "date_start":"2025-03-20", "date_end":"2025-03-20", "time_start":"11:00:00", "time_end":"12:00:00", "time_zone":"America\/Detroit", "event_title":"Great Lakes Seminar Series: David Lodge", "occurrence_title":"", "combined_title":"Great Lakes Seminar Series: David Lodge: The promises and perils of research in solving sustainability problems", "event_subtitle":"The promises and perils of research in solving sustainability problems", "event_type":"Lecture \/ Discussion", "event_type_id":"13", "description":"About the presentation: Researchers often assume that the value of research in solving problems is self-evident. Yet most research does not lead to solutions, even when the proposals that launched the research promised solutions. University and government researchers could address this longtime peril by including clear theories of change in project development, and co-creating and co-executing projects across disciplines and sectors. This would require alignment of funding and infrastructure to support such mission-driven research. In a rapidly changing government landscape, I will examine past examples of the role of research and technology development in driving change in policies, practices, and products. While I do not promise to resolve all the promises and perils, I will suggest some possible ways forward for solutions-oriented sustainability research in government and universities.\r\n\r\nAbout the speaker: Dr. David M. Lodge is the Francis J. DiSalvo director of Cornell University\u2019s Cornell Atkinson Center for Sustainability. He is an internationally recognized environmental scientist, with expertise in environmental risk assessment, freshwater and marine coastal ecology, ecosystem services, bioeconomics, and invasive species. His research has improved ecological forecasting to better inform environmental risk assessment, natural resource management, and policy development. Lodge is a leader in the development and application of environmental DNA (eDNA), a transformative technological tool for discovering unrecognized biodiversity, censusing aquatic biodiversity, and improving the management of imperiled, invasive, or harvested species. He is past president of the Ecological Society of America, and former senior science advisor in the US Department of State\u2019s Office of Polar Affairs. On numerous occasions he has testified before the U.S. Congress, and served as an expert witness in federal court. He is faculty member in the Department of Ecology and Evolutionary Biology at Cornell University.", "occurrence_notes":null, "guid":"132833-21871937@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/132833", "building_id":"null", "building_name":"Off Campus Location", "campus_maps_id":"1", "room":"", "location_name":"Virtual", "has_livestream":1, "livestream_type":"other", "livetream_require_login":0, "livestream_id":"", "livestream_link":"https:\/\/attendee.gotowebinar.com\/register\/6433568432537864539", "cost":"", "tags":["Public Policy","seminar","Research","Environmental Policy","Lecture","Great Lakes","Free"], "website":"https:\/\/ciglr.seas.umich.edu\/event\/032025-david-lodge\/", "sponsors":[ { "group_name":"Cooperative Institute for Great Lakes Research (CIGLR)", "group_id":"3432", "website":"http:\/\/ciglr.seas.umich.edu\/" } ], "image_url":"https:\/\/events.umich.edu\/media\/attachments\/2025\/02\/event_132833_original-1.jpeg", "styled_images":{ "event_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_thumb\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "event_large":"https:\/\/events.umich.edu\/media\/cache\/event_large\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "event_large_2x":"https:\/\/events.umich.edu\/media\/cache\/event_large_2x\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "event_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/event_large_lightbox\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "group_thumb":"https:\/\/events.umich.edu\/media\/cache\/group_thumb\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "group_thumb_square":"https:\/\/events.umich.edu\/media\/cache\/group_thumb_square\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "group_large":"https:\/\/events.umich.edu\/media\/cache\/group_large\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "group_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/group_large_lightbox\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "event_large_crop":"https:\/\/events.umich.edu\/media\/cache\/event_large_crop\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "event_list":"https:\/\/events.umich.edu\/media\/cache\/event_list\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "event_list_2x":"https:\/\/events.umich.edu\/media\/cache\/event_list_2x\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "event_grid":"https:\/\/events.umich.edu\/media\/cache\/event_grid\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "event_grid_2x":"https:\/\/events.umich.edu\/media\/cache\/event_grid_2x\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "event_feature_large":"https:\/\/events.umich.edu\/media\/cache\/event_feature_large\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg", "event_feature_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_feature_thumb\/media\/attachments\/2025\/02\/crop-event_132833_original-1.jpeg" }, "occurrence_count":2, "first_occurrence":21871936 } }