September 2026 - Cart-seminar - snurep.crystalline.site

CART seminar announcement (Andrew Hardt, Sep 18 (Fri), 10:00AM)
by 이신명 17 Sep '26

17 Sep '26

Dear all, The next CART seminar is scheduled for Sep. 18 (Fri), 10:00-11:00 in Korea time (9:00-10:00 in Beijing). Speaker: Andrew Hardt (Towson University, USA) Title: GL-multiplicities of type A quiver loci Abstract: The space of representations of a quiver admits an orbit structure via change of basis. When the quiver is type A, the orbit closures are described by rank conditions. These varieties generalize classical degeneracy loci. Their equations are understood through work of Zelevinsky and Kinser–Rajchgot, and their cohomology classes and K-polynomials have been computed by many authors, including Buch–Fulton, Knutson–Miller–Shimozono, Buch–Rimányi and Kinser–Knutson–Rajchgot. The coordinate ring of a quiver orbit closure is a rational representation of a product of general linear groups. In the special case of varieties of complexes, its irreducible decomposition is implicit in work of De Concini and Strickland. In joint work with Ian Cavey and Alexander Yong, we give a positive combinatorial rule for this decomposition, valid for all type A orbit closures in every orientation. Our rule is in terms of nonnegative integer matrices satisfying admissibility conditions corresponding to the rank conditions of the orbit closure. We put a crystal structure on these matrices, using the combinatorics of Stembridge's rational tableaux, and the irreducible multiplicities are counted by the highest weight admissible matrices. You can join the seminar via the following Zoom link: https://kias-re-kr.zoom.us/j/86352829715?pwd=KBrb6UvVv1myhwDmE7Xm59UUGsyKia… Meeting ID: 863 5282 9715 Password: 264696 Please feel free to forward this to anyone who might be interested. You can check out further information on CART seminar on our website (https://sites.google.com/view/cart-kias/). Looking forward to seeing you at the seminar! Best regards, Sin-Myung Lee

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(Reminder) CART seminar announcement (Rui Xiong, Sep 11 (Fri), 10:00AM)
by 이신명 10 Sep '26

10 Sep '26

Dear all, This is a gentle reminder of the CART seminar by Rui Xiong (University of Michigan) tomorrow at 10:00-11:00 in Korea time (9:00 - 10:00 in Beijing). Hope to see you at the seminar! Best regards, Sin-Myung Lee -----------------------원본 메세지----------------------- 보낸사람: "이신명"<sinmyunglee(a)kias.re.kr> 받는사람: "Mathematics Members(mathall)" <mathall(a)kias.re.kr>, cart-seminar(a)snurep.crystalline.site 참조: rxion043(a)uOttawa.ca 보낸날짜: 2026-09-06 20:38:47 GMT +0900 (Asia/Seoul)제목: CART seminar announcement (Rui Xiong, Sep 11 (Fri), 10:00AM) Dear all, We resume our CART seminar, whose first talk is scheduled for Sep. 11 (Fri), 10:00-11:00 in Korea time (9:00-10:00 in Beijing). Speaker: Rui Xiong (University of Michigan, USA) Title: A Proof of Butler's Positivity Conjecture Abstract: In this talk, I will present our recent proof of Butler's Schur positivity conjecture for Macdonald intersection polynomials (arXiv: 2608.11543). The proof uses the geometry of the Hilbert scheme of points in the affine plane. This is joint work with Peter Guo and Mingyang Kang. You can join the seminar via the following Zoom link: https://kias-re-kr.zoom.us/j/83006661943?pwd=0ZeKWRUD2KnGdjROgueVh2hqzXZjAk… Meeting ID: 830 0666 1943 Password: 603397 Please feel free to forward this to anyone who might be interested. You can check out further information on CART seminar on our website (https://sites.google.com/view/cart-kias/). Looking forward to seeing you at the seminar! Best regards, Sin-Myung Lee

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CART seminar announcement (Rui Xiong, Sep 11 (Fri), 10:00AM)
by 이신명 06 Sep '26

06 Sep '26

Dear all, We resume our CART seminar, whose first talk is scheduled for Sep. 11 (Fri), 10:00-11:00 in Korea time (9:00-10:00 in Beijing). Speaker: Rui Xiong (University of Michigan, USA) Title: A Proof of Butler's Positivity Conjecture Abstract: In this talk, I will present our recent proof of Butler's Schur positivity conjecture for Macdonald intersection polynomials (arXiv: 2608.11543). The proof uses the geometry of the Hilbert scheme of points in the affine plane. This is joint work with Peter Guo and Mingyang Kang. You can join the seminar via the following Zoom link: https://kias-re-kr.zoom.us/j/83006661943?pwd=0ZeKWRUD2KnGdjROgueVh2hqzXZjAk… Meeting ID: 830 0666 1943 Password: 603397 Please feel free to forward this to anyone who might be interested. You can check out further information on CART seminar on our website (https://sites.google.com/view/cart-kias/). Looking forward to seeing you at the seminar! Best regards, Sin-Myung Lee

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