An obstruction to lifting to characteristic 0. (English) Zbl 1536.14016
Summary: We introduce a new obstruction to lifting smooth proper varieties from characteristic \(p>0\) to characteristic 0. It is based on Grothendieck’s specialization homomorphism and the resulting discrete finiteness properties of étale fundamental groups.
MSC:
14F35 | Homotopy theory and fundamental groups in algebraic geometry |
11S15 | Ramification and extension theory |
11G20 | Curves over finite and local fields |
14G17 | Positive characteristic ground fields in algebraic geometry |