报告题目: Arithmetic purity of strong approximation

报告人: 徐飞，首都师范大学

时间:　11月29日，3:00-4:00

It is well-known that weak approximation is birational invariant between smooth varieties over number field by implicit function theorem. This is not true for strong approximation. For example, if a smooth variety satisfies strong approximation, then this variety must be simply connected. As Nagata-Zariski purity theorem, one can expect that if a smooth variety satisfies strong approximation, so does any open sub-variety with the codimension of the complement greater than 1. This is part of our joint program with Yang Cao and Yongqi Liang.