Abstract: 

The theta series of a positive definite quadratic lattice is a modular form. The geometric theta series of a hermitian lattice with sign (n-1,1) is a generating series of special divisors on unitary Shimura varieties, which is also modular. In this talk, I will give a review on the story and present results on the modularity of arithmetic theta series with parahoric levels.

Bio:

Zhang Zhiyu is a graduate student at MIT since 2018. His advisor is Professor Wei Zhang. During his last semester as an undergraduate (Spring 2018), he was visiting École normale supérieure.

Video:

http://archive.ymsc.tsinghua.edu.cn/pacm_lecture?html=Modularity_of_arithmetic_theta_series.html