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        "event_title":"The Ehrhart h*-polynomials of positroid polytopes (combinatorics seminar)",
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        "combined_title":"The Ehrhart h*-polynomials of positroid polytopes (combinatorics seminar): Yuhan Jiang (UC Berkeley)",
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        "description":"A positroid is a matroid realized by a matrix such that all maximal minors are non-negative. Positroid polytopes are matroid polytopes of positroids. In particular, they are lattice polytopes. The Ehrhart polynomial of a lattice polytope counts the number of integer points in the dilation of that polytope. The Ehrhart series is the generating function of the Ehrhart polynomial, which is a rational function with the numerator called the h^*-polynomial. We compute the h^*-polynomials of an arbitrary positroid polytope by a family of shelling orders of it. We also compute the h^*-polynomial of any positroid polytope with some facets removed, and we relate it to the descents of permutations. Our result generalizes that of Early, Kim, and Li for hypersimplices.",
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                "group_name":"Combinatorics Seminar - Department of Mathematics",
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        "datetime_modified":"20260130T120723",
        "datetime_start":"20260206T150000",
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        "event_title":"AIM Seminar:  Discrete Ricci Curvatures for Hypernetworks",
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        "combined_title":"AIM Seminar:  Discrete Ricci Curvatures for Hypernetworks: Emil Saucan (Braude College of Engineering, Israel)",
        "event_subtitle":"Emil Saucan (Braude College of Engineering, Israel)",
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        "description":"Abstract:  We present a brief overview of some notions of discrete curvatures for hypernetworks. In particular, we focus on the adaptation of the Forman-Ricci curvature to the hypernetworks setting, and its applications to genetic networks, more specifically to the understanding of dynamics pluripotent stem cells and cancer cells. We next concentrate on Ollivier-Ricci curvature based hypernetworks curvatures, and in particular on a newly proposed Ricci curvature for hypernetworks stemming from the generalized Wasserstein distance of Piccoli and Rossi and motivated, again, by biological networks.\n\nContact:  Indika Rajapakse",
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