{ "152479-21913801": { "datetime_modified":"20260920T103910", "datetime_start":"20260923T150000", "datetime_end":"20260923T160000", "has_end_time":1, "date_start":"2026-09-23", "date_end":"2026-09-23", "time_start":"15:00:00", "time_end":"16:00:00", "time_zone":"America\/Detroit", "event_title":"Profinite Rigidity and Hyperbolic Geometry", "occurrence_title":"", "combined_title":"Profinite Rigidity and Hyperbolic Geometry: Ari Benveniste", "event_subtitle":"Ari Benveniste", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"To what extent is a finitely presented group determined by its finite quotients? This question leads naturally to the profinite completion, which encodes all finite quotients of a group in a single algebraic object. In this talk, we will discuss work by Bridson, McReynolds, Reid, and Spitler who construct new examples of groups that are profinitely rigid, meaning they are uniquely determined by their profinite completion, via examples from hyperbolic geometry and low-dimensional topology. Their approach uses techniques involving representation rigidity, linking the finite quotients of a group to arithmetic invariants of lattices in PSL(2,C). If time permits, we will discuss more recent developments in this area pertaining to Dehn fillings of knots.", "occurrence_notes":null, "guid":"152479-21913801@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/152479", "building_id":"1000166", "building_name":"East Hall", "campus_maps_id":"53", "room":"1866", "location_name":"East Hall", "has_livestream":0, "cost":"", "tags":["Mathematics"], "website":"", "sponsors":[ { "group_name":"Student Dynamics\/Geometry\/Topology Seminar - Department of Mathematics", "group_id":"4909", "website":"" }, { "group_name":"Department of Mathematics", "group_id":"3791", "website":"" } ], "image_url":"", "styled_images":{ "event_thumb":"", "event_large":"", "event_large_2x":"", "event_large_lightbox":"", "group_thumb":"", "group_thumb_square":"", "group_large":"", "group_large_lightbox":"", "event_large_crop":"", "event_list":"", "event_list_2x":"", "event_grid":"", "event_grid_2x":"", "event_feature_large":"", "event_feature_thumb":"" }, "occurrence_count":1, "first_occurrence":21913801 } , "150200-21908388": { "datetime_modified":"20260818T120729", "datetime_start":"20260923T151000", "datetime_end":"20260923T161000", "has_end_time":1, "date_start":"2026-09-23", "date_end":"2026-09-23", "time_start":"15:10:00", "time_end":"16:10:00", "time_zone":"America\/Detroit", "event_title":"MIPSE Seminar | Laboratory Experiments of Astrophysical Processes in Magnetized Turbulence", "occurrence_title":"", "combined_title":"MIPSE Seminar | Laboratory Experiments of Astrophysical Processes in Magnetized Turbulence: Prof. Petros Tzeferacos, University of Rochester", "event_subtitle":"Prof. Petros Tzeferacos, University of Rochester", "event_type":"Lecture \/ Discussion", "event_type_id":"13", "description":"Abstract: \nMagnetized turbulence in the interstellar and intergalactic mediums is a key agent affecting or governing the phenomenology observed in such astrophysical environments. In this seminar, I present fundamental science research in magnetized astrophysical plasmas that is accomplished through the concerted application of simulation codes and laboratory plasma astrophysics experiments. I discuss studies in fluctuation dynamo, a ubiquitous astrophysical process thought to be responsible for the present-day magnetization of numerous celestial objects; charged particle diffusive transport and acceleration, in the context of extragalactic and ultra-high energy cosmic rays; and the transport of heat in galaxy clusters. The experiments leverage world-class laser facilities like the Omega Laser Facility at the Laboratory for Laser Energetics, the National Ignition Facility at Lawrence Livermore National Laboratory, and the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt. We detail these experiments, as well as the FLASH simulation campaigns that we executed for their design and interpretation, providing us with new way to validate or falsify our theoretical understanding. The work reflects the efforts of the TDYNO (Turbulent Dynamo) collaboration.\n\nWe acknowledge support by the U.S. DOE NNSA; the U.S. DOE Office of Science; and the U. S. National Science Foundation. We also acknowledge support from UK Research and Innovation.\n\nAbout the Speaker: \nPetros Tzeferacos is the Director of Flash Center for Computational Science, a Professor of Physics and Astronomy, and a Senior Scientist at the Laboratory for Laser Energetics of the University of Rochester. He works on plasma physics and astrophysics, combining MHD theory, numerical modeling, and laser-driven laboratory experiments, to study fundamental astrophysical plasma processes with a focus on magnetized turbulence, dynamo, and charged particle acceleration. He is also working on several fundamental topics in inertial fusion energy and high energy density physics. He holds a visiting scientist position with the University of Oxford and the Lawrence Livermore National Laboratory and is a guest scientist at Los Alamos National Laboratory. He received the APS John Dawson Award for Excellence in Plasma Physics Research in 2019, an Early Career Award from the U.S. Department of Energy Office of Science in 2021, and the Presidential Early Career Award for Scientists and Engineers in 2025.\n\nThe seminar will be conducted in person, with livestream on Zoom. For more information, please check the MIPSE website: https:\/\/mipse.umich.edu\/seminars_2627.php#fall2026", "occurrence_notes":null, "guid":"150200-21908388@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/150200", "building_id":"1000448", "building_name":"Electrical Engineering and Computer Science Building", "campus_maps_id":"56", "room":"1003", "location_name":"Electrical Engineering and Computer Science Building", "has_livestream":0, "cost":"", "tags":["Astrophysics","Michigan Engineering","Physics","Plasma","Research","seminar"], "website":"https:\/\/mipse.umich.edu\/seminars_2627.php", "sponsors":[ { "group_name":"Michigan Institute for Plasma Science and Engineering (MIPSE)", "group_id":"4073", "website":"" } ], "image_url":"https:\/\/events.umich.edu\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "styled_images":{ "event_thumb":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_thumb\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "event_large":"https:\/\/events.umich.edu\/media\/cache\/event_large\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "event_large_2x":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_large_2x\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "event_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/event_large_lightbox\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "group_thumb":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_thumb\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "group_thumb_square":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_thumb_square\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "group_large":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_large\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "group_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_large_lightbox\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "event_large_crop":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_large_crop\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "event_list":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_list\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "event_list_2x":"https:\/\/events.umich.edu\/media\/cache\/event_list_2x\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "event_grid":"https:\/\/events.umich.edu\/media\/cache\/event_grid\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "event_grid_2x":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_grid_2x\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "event_feature_large":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_feature_large\/media\/attachments\/2026\/08\/event_150200_original-1.jpg", "event_feature_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_feature_thumb\/media\/attachments\/2026\/08\/event_150200_original-1.jpg" }, "occurrence_count":1, "first_occurrence":21908388 } , "149714-21906987": { "datetime_modified":"20260920T090237", "datetime_start":"20260923T153000", "datetime_end":"20260923T165000", "has_end_time":1, "date_start":"2026-09-23", "date_end":"2026-09-23", "time_start":"15:30:00", "time_end":"16:50:00", "time_zone":"America\/Detroit", "event_title":"Algebraic Geometry Seminar -- Regular polyhedra over finite fields and triangular modular curves", "occurrence_title":"", "combined_title":"Algebraic Geometry Seminar -- Regular polyhedra over finite fields and triangular modular curves: Caleb Ji, University of Michigan", "event_subtitle":"Caleb Ji, University of Michigan", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"Through creating undergraduate course materials, Grothendieck was led to define a new notion of regular polyhedra that holds over arbitrary base rings. He asked in *Esquisse d'un Programme* for a classification of them over finite fields. In this talk, we will give an answer using the theory of triangular modular curves. Through this we also compute some new cases of monodromy groups of triangular modular curves. This is joint work with John Voight.", "occurrence_notes":null, "guid":"149714-21906987@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/149714", "building_id":"1000166", "building_name":"East Hall", "campus_maps_id":"53", "room":"4096", "location_name":"East Hall", "has_livestream":0, "cost":"", "tags":["Mathematics"], "website":"", "sponsors":[ { "group_name":"Algebraic Geometry Seminar - Department of Mathematics", "group_id":"4880", "website":"" }, { "group_name":"Department of Mathematics", "group_id":"3791", "website":"" } ], "image_url":"", "styled_images":{ "event_thumb":"", "event_large":"", "event_large_2x":"", "event_large_lightbox":"", "group_thumb":"", "group_thumb_square":"", "group_large":"", "group_large_lightbox":"", "event_large_crop":"", "event_list":"", "event_list_2x":"", "event_grid":"", "event_grid_2x":"", "event_feature_large":"", "event_feature_thumb":"" }, "occurrence_count":1, "first_occurrence":21906987 } , "152487-21913817": { "datetime_modified":"20260922T042123", "datetime_start":"20260923T153000", "datetime_end":"20260923T163000", "has_end_time":1, "date_start":"2026-09-23", "date_end":"2026-09-23", "time_start":"15:30:00", "time_end":"16:30:00", "time_zone":"America\/Detroit", "event_title":"SMTD Dual Degree Social Mixer - Welcome Back SMTD!", "occurrence_title":"", "combined_title":"SMTD Dual Degree Social Mixer - Welcome Back SMTD!", "event_subtitle":"", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"Join SMTD Student Success for a gathering of SMTD students pursuing a second degree from another UM school (LSA, CoE, etc.)! Panda Express, treats, and a variety of board games will be provided. This is a drop-in event, so feel free to stop by as your schedule allows. Food and Beverages will be provided.\u00a0", "occurrence_notes":null, "guid":"152487-21913817@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/152487", "building_id":"", "building_name":"", "campus_maps_id":"", "room":"", "location_name":"Student Commons", "has_livestream":0, "cost":"", "tags":["Sessions"], "website":"https:\/\/sessions.studentlife.umich.edu\/p\/track\/18053", "sponsors":[ { "group_name":"Sessions @ Michigan", "group_id":"4791", "website":"https:\/\/sessions.studentlife.umich.edu\/" } ], "image_url":"", "styled_images":{ "event_thumb":"", "event_large":"", "event_large_2x":"", "event_large_lightbox":"", "group_thumb":"", "group_thumb_square":"", "group_large":"", "group_large_lightbox":"", "event_large_crop":"", "event_list":"", "event_list_2x":"", "event_grid":"", "event_grid_2x":"", "event_feature_large":"", "event_feature_thumb":"" }, "occurrence_count":1, "first_occurrence":21913817 } , "149578-21906720": { "datetime_modified":"20260727T104702", "datetime_start":"20260923T160000", "datetime_end":"20260923T170000", "has_end_time":1, "date_start":"2026-09-23", "date_end":"2026-09-23", "time_start":"16:00:00", "time_end":"17:00:00", "time_zone":"America\/Detroit", "event_title":"Buying Time: Optimal Service Purchase and Retirement Timing in Defined Benefit Plans", "occurrence_title":"", "combined_title":"Buying Time: Optimal Service Purchase and Retirement Timing in Defined Benefit Plans: Kristen Moore, UM", "event_subtitle":"Kristen Moore, UM", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"We study retirement timing decisions in a defined benefit (DB) pension plan with a service-purchase\noption. An employee who would otherwise retire at a fixed time T may elect to purchase L additional\nyears of service and retire early. Earlier retirement provides additional leisure but requires an upfront\npayment and typically results in a reduced post-retirement income stream. We model this trade-off in\na continuous-time retirement framework by allowing the employee to choose L to maximize the value\nof wealth and leisure at retirement in both deterministic and life-contingent settings. Our model\ncaptures a common feature of public pension systems: early retirement is often accompanied by both\nan upfront cost and a permanent reduction in benefits. We show that this structure yields tractable\nand intuitive results in several benchmark cases, including settings without mortality risk and settings\nwith mortality risk under simplifying assumptions. In more general cases, we characterize optimal\nbehavior through comparative statics and numerical examples. A key insight is that the interaction\nbetween the finite-horizon value of leisure and the lifetime cost embedded in pension pricing can\ngenerate a range of behaviors, including monotone strategies and interior optima. While many results\nalign with economic intuition, others require more careful interpretation. We also extend the model to\nallow for dynamic decision-making via a multi-period service-purchase option, solved by backward\ninduction. The results provide insight into optimal retirement timing and the role of plan design in\nshaping participant behavior. This is joint work with David Kausch and Virginia Young.", "occurrence_notes":null, "guid":"149578-21906720@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/149578", "building_id":"1000166", "building_name":"East Hall", "campus_maps_id":"53", "room":"1360", "location_name":"East Hall", "has_livestream":0, "cost":"", "tags":["Mathematics"], "website":"", "sponsors":[ { "group_name":"Financial\/Actuarial Mathematics Seminar - Department of Mathematics", "group_id":"4890", "website":"" }, { "group_name":"Department of Mathematics", "group_id":"3791", "website":"" } ], "image_url":"", "styled_images":{ "event_thumb":"", "event_large":"", "event_large_2x":"", "event_large_lightbox":"", "group_thumb":"", "group_thumb_square":"", "group_large":"", "group_large_lightbox":"", "event_large_crop":"", "event_list":"", "event_list_2x":"", "event_grid":"", "event_grid_2x":"", "event_feature_large":"", "event_feature_thumb":"" }, "occurrence_count":1, "first_occurrence":21906720 } }