Title: Towards three problems of Katz on Kloosterman sums Speaker: Prof. Ping Xi (Xi'an Jiaotong University) Time: 2020-6-24, 16:00-17:00 Place: http://www.mcm.ac.cn/activities/programs/znts/202006/t20200609_564205.html Abstract: Motivated by deep observations on elliptic curves, Nicholas Katz proposed three problems on sign changes, equidistributions and modular structures of Kloosterman sums in 1980. In this talk, we will discuss some recent progresses towards these three problems made by analytic number theory combining certain tools from $\ell$-adic cohomology. Attachment: