{ "128994-21861997": { "datetime_modified":"20241111T073642", "datetime_start":"20241114T160000", "datetime_end":"20241114T170000", "has_end_time":1, "date_start":"2024-11-14", "date_end":"2024-11-14", "time_start":"16:00:00", "time_end":"17:00:00", "time_zone":"America\/Detroit", "event_title":"Rep Stability\/Comm Alg Seminar: Stabilization of infinite powers of varieties of tensors", "occurrence_title":"", "combined_title":"Rep Stability\/Comm Alg Seminar: Stabilization of infinite powers of varieties of tensors: Alessandro Danelon", "event_subtitle":"Alessandro Danelon", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"Draisma proved that infinite dimensional varieties of tensors, defined uniformly with respect to the base vector space, are topologically Noetherian up to the action of the general linear group.The infinite power Z^N of a finite dimensional variety Z is ring-theoretically Noetherian up to the action of the infinite symmetric group permuting the copies of Z. We show that infinite powers of infinite dimensional varieties of tensors are defined set-theoretically by the Sym x GL-orbits of finitely many equations. This talk will browse these results.\r\nJoint work with Chiu, Draisma, Eggermont, and Farooq.", "occurrence_notes":null, "guid":"128994-21861997@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/128994", "building_id":"1000166", "building_name":"East Hall", "campus_maps_id":"53", "room":"3088", "location_name":"East Hall", "has_livestream":0, "cost":"", "tags":["Mathematics"], "website":"", "sponsors":[ { "group_name":"Department of Mathematics", "group_id":"3791", "website":"" }, { "group_name":"Commutative Algebra Seminar - Department of Mathematics", "group_id":"4886", "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":21861997 } , "127744-21859608": { "datetime_modified":"20241112T120149", "datetime_start":"20241114T160000", "datetime_end":"20241114T170000", "has_end_time":1, "date_start":"2024-11-14", "date_end":"2024-11-14", "time_start":"16:00:00", "time_end":"17:00:00", "time_zone":"America\/Detroit", "event_title":"Student DGT", "occurrence_title":"", "combined_title":"Student DGT: Jordan Grant: Automatic Ping Pong", "event_subtitle":"Jordan Grant: Automatic Ping Pong", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"Abstract: The Ping-Pong Lemma is a well known statement in geometric group theory which lets us prove a group \u0393 is free by finding subsets of a space X which \u0393 acts on that meet certain conditions. I will be discussing a recent generalization of the ping pong lemma in the context of group actions on projective space. Using this result I will describe an algorithm which can calculate explicit bounds on the size of the kernel of a representation of certain finitely generated groups into SL(2, R).", "occurrence_notes":null, "guid":"127744-21859608@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/127744", "building_id":"1000166", "building_name":"East Hall", "campus_maps_id":"53", "room":"2866", "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":21859608 } , "126400-21857080": { "datetime_modified":"20260218T195929", "datetime_start":"20241114T160000", "datetime_end":"20241114T170000", "has_end_time":1, "date_start":"2024-11-14", "date_end":"2024-11-14", "time_start":"16:00:00", "time_end":"17:00:00", "time_zone":"America\/Detroit", "event_title":"Topology seminar: The Second Rational Homology of the Torelli Group", "occurrence_title":"", "combined_title":"Topology seminar: The Second Rational Homology of the Torelli Group: Dan Minahan (University of Chicago)", "event_subtitle":"Dan Minahan (University of Chicago)", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"The Torelli group is the subgroup of the mapping class group of a surface acting trivially on the first homology of the surface. The first rational homology of the Torelli group is known for a closed surface of genus 2 by work of Mess, and for closed surfaces of genus at least 3 by work of Johnson. We will discuss forthcoming work with Putman that computes the second rational homology of the Torelli group for all closed surfaces of genus at least 6. In particular, we will show that this homology group is an algebraic representation of the symplectic group. Combined with the work of Kupers and Randal-Williams, this partially resolves Church and Farb's conjecture that the rational homology of the Torelli group is representation stable over the symplectic group.", "occurrence_notes":null, "guid":"126400-21857080@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/126400", "building_id":"1000166", "building_name":"East Hall", "campus_maps_id":"53", "room":"3866", "location_name":"East Hall", "has_livestream":0, "cost":"", "tags":["Mathematics"], "website":"", "sponsors":[ { "group_name":"Topology Seminar - Department of Mathematics", "group_id":"4910", "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":21857080 } }