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 |
