{
    "154396-21917646":
    {
        "datetime_modified":"20261101T133035",
        "datetime_start":"20261102T160000",
        "datetime_end":"20261102T170000",
        "has_end_time":1,
        "date_start":"2026-11-02",
        "date_end":"2026-11-02",
        "time_start":"16:00:00",
        "time_end":"17:00:00",
        "time_zone":"America\/Detroit",
        "event_title":"How plabic graphs describe weakly separated collections",
        "occurrence_title":"",
        "combined_title":"How plabic graphs describe weakly separated collections: Veronica Lang",
        "event_subtitle":"Veronica Lang",
        "event_type":"Workshop \/ Seminar",
        "event_type_id":"21",
        "description":"Two k-element subsets I,J of {1,2,\u2026,n} are weakly separated if the sets I\\J and J\\I (when drawn on a circle with vertices 1,2,\u2026,n) can be separated by a chord. A maximal weakly separated collection is a set of pairwise weakly-separated k-element subsets of {1,2,\u2026,n} that is not contained in any larger set with this property. This definition gives rise to natural combinatorial questions: How big is a maximal weakly separated collection? How many are there? How are they related to each other?\n\nI will outline how Oh, Posknikov, Speyer answered most of these questions via a bijection between maximal weakly separated collections in a positroid and move-equivalent plabic graphs. Along the way, we\u2019ll meet some fun combinatorial objects related to plabic graphs including bounded affine permutations, Grassmann necklaces, positroids, and plabic tilings.",
        "occurrence_notes":null,
                "guid":"154396-21917646@events.umich.edu",
        "permalink":"http:\/\/events.umich.edu\/event\/154396",
        "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":"Student Combinatorics Seminar - Department of Mathematics",
                "group_id":"4907",
                "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":21917646
    }    ,    "153397-21915803":
    {
        "datetime_modified":"20261007T095927",
        "datetime_start":"20261102T160000",
        "datetime_end":"20261102T170000",
        "has_end_time":1,
        "date_start":"2026-11-02",
        "date_end":"2026-11-02",
        "time_start":"16:00:00",
        "time_end":"17:00:00",
        "time_zone":"America\/Detroit",
        "event_title":"ISRMT Seminar: Title TBA",
        "occurrence_title":"",
        "combined_title":"ISRMT Seminar: Title TBA: Adam Doliwa (University of Warmia and Mazury in Olsztyn)",
        "event_subtitle":"Adam Doliwa (University of Warmia and Mazury in Olsztyn)",
        "event_type":"Workshop \/ Seminar",
        "event_type_id":"21",
        "description":"Abstract: TBA",
        "occurrence_notes":null,
                "guid":"153397-21915803@events.umich.edu",
        "permalink":"http:\/\/events.umich.edu\/event\/153397",
        "building_id":"null",
        "building_name":"Off Campus Location",
        "campus_maps_id":"1",
        "room":"",
        "location_name":"Virtual",
        "has_livestream":0,
        "cost":"",
        "tags":["Mathematics"],
        "website":"",
        "sponsors":[
             {
                "group_name":"Integrable Systems and Random Matrix Theory Seminar - Department of Mathematics",
                "group_id":"4893",
                "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":21915803
    }    }