# Gromov-Witten Theory and Cycle-Valued Modular Forms

 Joint IAS-PU Symplectic Geometry Seminar Topic: Gromov-Witten Theory and Cycle-Valued Modular Forms Speaker: Yefeng Shen Affiliation: University of Michigan Date: Friday, November 30 Time/Room: 1:30pm - 2:30pm/Fine Hall 401

A remarkable phenomenon in Gromov-Witten theory is the appearance of (quasi)-modular forms. For example, Gromov-Witten generating functions for elliptic curve, local $\mathbb{P}^2$, elliptic orbifold $\mathbb{P}^1$ are all (quasi)-modular forms. In this talk, we will discuss modularity property of the Gwomov-Witten cycles of elliptic orbifold $\mathbb{P}^1$. Since Gromov-Witten cycles live in the cohomology space of moduli of pointed curves, our result gives a geometric realization of a collection of vector-valued (quasi)-modularity forms via Gromov-Witten theory. This work is joint with Todor Milanov and Yongbin Ruan.