{ "152055-21912772": { "datetime_modified":"20260930T173806", "datetime_start":"20261005T160000", "datetime_end":"20261005T170000", "has_end_time":1, "date_start":"2026-10-05", "date_end":"2026-10-05", "time_start":"16:00:00", "time_end":"17:00:00", "time_zone":"America\/Detroit", "event_title":"ISRMT Seminar: Extremal Problems Motivated by Focusing NLS Condensates", "occurrence_title":"", "combined_title":"ISRMT Seminar: Extremal Problems Motivated by Focusing NLS Condensates: Alexander Tovbis (University of Central Florida)", "event_subtitle":"Alexander Tovbis (University of Central Florida)", "event_type":"Presentation", "event_type_id":"16", "description":"Abstract: Soliton gases for integrable systems is a rapidly developing new area in the theory of nonlinear waves. For a given spectral support set, a soliton gas of maximal average intensity is called soliton condensate. A spectral support set for a fNLS soliton condensate is often represented by a finite collection of points (anchors) E in the upper half plane H, connected with each other and\/or with the real axis by some set of (Schwarz symmetrical) arcs. Given a set of anchors E, a natural question is to find a collection of such arcs that produces fNLS soliton condensate of minimal average intensity. That leads to a modification of the well-known Chebotarev\u2019s continuum problem, which consists in finding a continuum K \u2282 C of minimal logarithmic capacity that contains a given set of anchors E \u2282 C. In this talk, we discuss our solution to the modified Chebotarev\u2019s problem, where E and K are subsets of the upper half plane H and where we minimize the Dirichlet energy of H \\ K instead of the logarithmic capacity of K. This is a joint work with Marco Bertola.", "occurrence_notes":null, "guid":"152055-21912772@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/152055", "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":"Integrable Systems and Random Matrix Theory Seminar - Department of Mathematics", "group_id":"4893", "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":21912772 } , "152449-21913751": { "datetime_modified":"20261002T130230", "datetime_start":"20261012T160000", "datetime_end":"20261012T170000", "has_end_time":1, "date_start":"2026-10-12", "date_end":"2026-10-12", "time_start":"16:00:00", "time_end":"17:00:00", "time_zone":"America\/Detroit", "event_title":"ISRMT Seminar: On Fredholm Pfaffians and Riemann-Hilbert problems", "occurrence_title":"", "combined_title":"ISRMT Seminar: On Fredholm Pfaffians and Riemann-Hilbert problems: Amari Jaconelli (University of Bristol)", "event_subtitle":"Amari Jaconelli (University of Bristol)", "event_type":"Livestream \/ Virtual", "event_type_id":"24", "description":"Abstract: In this talk, I will illustrate how classes of Fredholm Pfaffians, which can describe the eigenvalue distributions for orthogonal and symplectic matrix ensembles, can be computed in terms of canonical, auxiliary Riemann-Hilbert problems.\nThis is done by first algebraically manipulating the kernel of the Fredholm Pfaffian and then relating the resulting Pfaffian to a Riemann-Hilbert problem, assuming its main kernel is either of additive Hankel composition or truncated Wiener-Hopf type. One can then find asymptotic results for the Fredholm Pfaffian as a natural consequence of the Rieman-Hilbert problem characterisation.\nThis talk is based on my paper with Thomas Bothner, currently available in preprint on the arXiv: https:\/\/arxiv.org\/abs\/2511.23362. \n\n*To request access to the Zoom room, please contact Nathan Hayford at nhayford [ at ] umich.edu.*", "occurrence_notes":null, "guid":"152449-21913751@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/152449", "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":"" } ], "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":21913751 } , "153062-21915026": { "datetime_modified":"20260929T150501", "datetime_start":"20261026T160000", "datetime_end":"20261026T170000", "has_end_time":1, "date_start":"2026-10-26", "date_end":"2026-10-26", "time_start":"16:00:00", "time_end":"17:00:00", "time_zone":"America\/Detroit", "event_title":"Long time asymptotics of the generalized soliton gas for the mKdV equation", "occurrence_title":"", "combined_title":"Long time asymptotics of the generalized soliton gas for the mKdV equation: Manuela Girotti (Emory University)", "event_subtitle":"Manuela Girotti (Emory University)", "event_type":"Livestream \/ Virtual", "event_type_id":"24", "description":"We analyze a new class of solutions of the modified KdV equation introduced by Dyachenko, Zakharov, and Zakharov, and which can be interpreted as a soliton gas. These solutions are characterized by a Riemann-Hilbert problem which arises as the limit $N\\to \\infty$ of a sequence of $2N$-soliton RH problems, where the solitons display two different triangularity in the jumps. The limiting RH problem belongs to a novel class of problems, where the jump matrices do not have any zero entry (as opposed to the classical upper\/lower triangular setting).\n We show that the initial profile of such a gas solution is approaching a cnoidal wave solution for $x\\to \\pm \\infty$ with different phase shifts, and we establish an asymptotic description of the gas of solitons for large times that is valid over the entire spatial domain, in terms of Jacobi elliptic functions, with slowly modulated phase shifts as time varies from $-\\infty$ to $+\\infty$.\nThis is a joint work with Ken McLaughlin (Tulane U.) and Robert Jenkins (UCF).\n\n*To request access to the Zoom room, please contact Nathan Hayford at nhayford [ at ] umich.edu.*", "occurrence_notes":null, "guid":"153062-21915026@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/153062", "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":"" } ], "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":21915026 } , "153025-21914934": { "datetime_modified":"20260928T205020", "datetime_start":"20261116T160000", "datetime_end":"20261116T170000", "has_end_time":1, "date_start":"2026-11-16", "date_end":"2026-11-16", "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: Amol Aggarwal (Stanford University)", "event_subtitle":"Amol Aggarwal (Stanford University)", "event_type":"Livestream \/ Virtual", "event_type_id":"24", "description":"Abstract: TBA\n*To request access to the Zoom room, please contact Nathan Hayford at nhayford [ at ] umich.edu*", "occurrence_notes":null, "guid":"153025-21914934@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/153025", "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":"" } ], "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":21914934 } , "153029-21914939": { "datetime_modified":"20260929T085739", "datetime_start":"20261207T160000", "datetime_end":"20261207T170000", "has_end_time":1, "date_start":"2026-12-07", "date_end":"2026-12-07", "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: Yvonne Alama Bronsard (CNRS, Nantes)", "event_subtitle":"Yvonne Alama Bronsard (CNRS, Nantes)", "event_type":"Presentation", "event_type_id":"16", "description":"Abstract: TBA", "occurrence_notes":null, "guid":"153029-21914939@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/153029", "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":"Integrable Systems and Random Matrix Theory Seminar - Department of Mathematics", "group_id":"4893", "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":21914939 } }