{ "142441-21890960": { "datetime_modified":"20260120T120501", "datetime_start":"20260130T143000", "datetime_end":"20260130T153000", "has_end_time":1, "date_start":"2026-01-30", "date_end":"2026-01-30", "time_start":"14:30:00", "time_end":"15:30:00", "time_zone":"America\/Detroit", "event_title":"An introduction to webs (Combinatorics seminar)", "occurrence_title":"", "combined_title":"An introduction to webs (Combinatorics seminar): Julianna Tymoczko (Smith)", "event_subtitle":"Julianna Tymoczko (Smith)", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"The combinatorial spider is a diagrammatic category that encodes quantum sl(n) representations, and was formalized by Kuperberg. Webs are certain directed planar graphs (with edge-weights), corresponding to the morphisms in this category, and endowed with skein-type relations that indicate algebraic equivalences. Webs are well-understood in the case n=2, when they are essentially noncrossing matchings (or Temperley-Lieb diagrams), and in the substantially more complicated case n=3. \n\nIn this talk, we sketch some of the historical evolution of webs, including work of Kuperberg, Khovanov, Fontaine, and Cautis-Kamnitzer-Morrison, as well as the convergence with a collection of combinatorial ideas about plabic graphs from Postnikov, Fomin-Pylyavskyy, Fraser-Lam-Le, and others. We also describe a new approach, joint with Heather M. Russell, that uses a set of colored paths called \\emph{strands} to give a global construction for webs, via graph-theoretic and combinatorial notions generalized from smaller dimensions. Time permitting, we'll also allude to connections to algebraic geometry.", "occurrence_notes":null, "guid":"142441-21890960@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/142441", "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":"Combinatorics Seminar - Department of Mathematics", "group_id":"4885", "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":21890960 } , "141895-21889610": { "datetime_modified":"20260121T171348", "datetime_start":"20260130T150000", "datetime_end":"20260130T160000", "has_end_time":1, "date_start":"2026-01-30", "date_end":"2026-01-30", "time_start":"15:00:00", "time_end":"16:00:00", "time_zone":"America\/Detroit", "event_title":"AIM Seminar: The Algebra of Scientific Doubt: From Noether to Noise, from Ritt to the Unknown", "occurrence_title":"", "combined_title":"AIM Seminar: The Algebra of Scientific Doubt: From Noether to Noise, from Ritt to the Unknown: Lior Horesh (IBM Research)", "event_subtitle":"Lior Horesh (IBM Research)", "event_type":"Lecture \/ Discussion", "event_type_id":"13", "description":"Abstract: Scientific progress is defined by a fundamental asymmetry: a theory feels complete until the moment it is proven wrong. In mathematical modeling, we often operate within axiomatic systems, (conservation laws, symmetries, and invariants), that are inevitably incomplete. The central challenge of automated discovery is abduction: can we reason backward from observed phenomena to identify the missing principles that our axioms fail to capture?\n\nIn this talk, I will outline a program for the systematic discovery of physical laws through the lens of algebraic geometry. Building on the AI-Noether framework, which utilized Hilbert's Nullstellensatz and Noether's primary decomposition (I=\u22c2qi) for abductive discovery in exact polynomial settings, we now extend this machinery into two new frontiers. \n\nFirst, we address the \"brittleness\" of symbolic computation by embracing Numerical Algebraic Geometry. Using homotopy continuation and witness sets, we move beyond exact arithmetic to achieve scalable, noise-robust inference in empirical data. Second, we transition from static constraints to dynamical systems via Differential Algebra. By shifting from Hilbert\u2019s Basis Theorem to Ritt\u2019s, and from Gr\u00f6bner bases to Rosenfeld-Gr\u00f6bner characteristic sets, we enable the native discovery of differential equations directly from observations.\n\nThe power of this synthesis is already emerging. Preliminary applications to a series of long-standing open problems in mathematical physics suggest that this framework can identify candidate laws and hidden symmetries where classical derivation has stalled. We are finally positioned to venture into genuinely unknown territory: the discovery of fundamental principles that have remained, until now, just beyond human reach.\n\nContact: Shravan Veerapaneni", "occurrence_notes":null, "guid":"141895-21889610@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/141895", "building_id":"1000166", "building_name":"East Hall", "campus_maps_id":"53", "room":"1084", "location_name":"East Hall", "has_livestream":0, "cost":"", "tags":["Mathematics"], "website":"", "sponsors":[ { "group_name":"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics", "group_id":"4882", "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":21889610 } }