06-28【Alessandro Giacchetto&Nitin Chidambaram】腾讯会议 清华-中科大联合讨论班报告


题目 : Negative over positive I: the cohomology class

         Negative over positive II: integrability

报告人:Alessandro Giacchetto & Nitin Chidambaram

时间 : June 28, 2022, 15:00-16:30

         July 5, 2022, 15:00-16:30

腾讯会议: 572-283-2445 密码: 123456

摘要 : In the first talk (by Alessandro Giacchetto), we will present the construction and properties of a cohomological field theory (without a flat unit) that parallels the famous Witten r-spin class for “negative” spin. The case r=2 was constructed by Norbury in 2017. By studying certain deformations of this class, we prove relations in the tautological ring, and in the special case of r=2 they reduce to relations involving only kappa classes which were recently conjectured by Norbury–Kazarian. In the second talk (by Nitin Chidambaram), we will exploit the relation between cohomological field theories and topological recursion to prove W-algebra constraints satisfied by the descendant potential of the class. Furthermore, we conjecture that this descendant potential is the r-BGW tau function of the r-KdV hierarchy, and prove it for r=2 (confirming a conjecture of Norbury) and r=3. This is based on the following joint work with Elba Garcia-Failde: https://arxiv.org/pdf/2205.15621.pdf