Dear all,

This is a gentle reminder of the CART seminar by Soyeon Kim (UC Davis) tomorrow at 10:30 - 11:30 in Korea time (9:30 - 10:30 in Beijing).

Hope to see you at the seminar!

Best regards,

Sin-Myung Lee

-----------------------원본 메세지----------------------- 보낸사람: "이신명"sinmyunglee@kias.re.kr 받는사람: "Mathematics Members(mathall)" mathall@kias.re.kr, cart-seminar@snurep.crystalline.site 참조: syxkim@math.ucdavis.edu 보낸날짜: 2026-05-26 22:59:38 GMT +0900 (Asia/Seoul) 제목: CART seminar announcement (Soyeon Kim, Jun 5 (Fri), 10:30AM)

Dear all,

The next CART seminar is scheduled for June 5th (Fri), 10:30 - 11:30 in Korea time (9:30 - 10:30 in Beijing).

Speaker: Soyeon Kim (UC Davis)  Title: Unexpected toric Richardson varieties Abstract: In this talk, we introduce a new class of toric Richardson varieties, which we call unexpected toric Richardson varieties. These Richardson varieties are toric varieties with respect to the action of a torus of higher dimension (compared to the standard torus case), whose torus action was previously completely unexplored. The standard torus action on Richardson varieties and a characterization of (expected) toric Richardsons with respect to the standard torus were well understood. The existence of such unexpected toric Richardsons were implied by our characterization result for all toric Richardson varieties: the open Richardson variety $R_{v,w}$ in the complete flag variety is a torus $\mathbb{T}$ if and only if the closed Richardson variety $\overline{R}_{v,w}$ is a toric variety with respect to $\mathbb{T}$. Equivalently, this can be said that when the Bruhat interval $[ v , w ] $ is a lattice. Moreover, we prove that similar to the standard torus case, the moment polytopes for all toric Richardson varieties have a nice combinatorial description in terms of Bruhat interval. This is based on my joint work with Eugene Gorsky and Melissa Sherman-Bennett.

You can join the seminar via the following

Zoom link: https://kias-re-kr.zoom.us/j/86733679216?pwd=K7Nm3op6PSzkL4PRDtyKiKSavdIayw.... ID: 867 3367 9216 password: 067888

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