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        "event_title":"Trees and SL2",
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        "combined_title":"Trees and SL2: Aaron Kim",
        "event_subtitle":"Aaron Kim",
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        "description":"A common theme in mathematics is to understand algebraic objects using their actions on geometric spaces. Bass\u2014Serre theory is one instance of this approach where one studies groups via their actions on trees. I will give an introduction to the simplest case of Bass\u2014Serre theory and build a dictionary between gluing of spaces, amalgamation of groups, and actions on trees. This dictionary gives us a surprising amount of information about the structure of groups, especially about their torsion subgroups. I will demonstrate this by applying the theory to SL2(Z), SL2(Q_p), and SL2(F_p((t))).",
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                "group_name":"Student Dynamics\/Geometry\/Topology Seminar - Department of Mathematics",
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        "datetime_modified":"20260114T220853",
        "datetime_start":"20260128T153000",
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        "has_end_time":1,
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        "event_title":"Algebraic Geometry Seminar: On the P=C conjecture",
        "occurrence_title":"",
        "combined_title":"Algebraic Geometry Seminar: On the P=C conjecture: Woonam Lim (Yonsei University)",
        "event_subtitle":"Woonam Lim (Yonsei University)",
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        "event_type_id":"21",
        "description":"I will introduce the P=C conjecture which is an analogue of the P=W conjecture in the setting of a del Pezzo surface S. The main character of the conjecture is the moduli space M of one-dimensional sheaves on S. The perverse filtration records the topology of the Hitchin-type fibration, while the Chern filtration records the shape of tautological relations. The perverse filtration is of particular interest because it conjecturally categorifies the Gopakumar-Vafa invariants of a local Calabi-Yau 3-fold. This is a joint work with Y. Kononov, M. Moreira, W. Pi.",
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                "group_name":"Algebraic Geometry Seminar - Department of Mathematics",
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