--- created: 2023-04-17T12:22 updated: 2024-01-01T23:13 --- --- date: 2022-09-28 15:27 modification date: Wednesday 28th September 2022 15:27:58 title: "2022-09-28" aliases: [2022-09-28] --- Last modified date: NaN --- - Tags: - #todo/untagged - Refs: - #todo/add-references - Links: - #todo/create-links --- # 2022-09-28 To look up: - [ ] [plurigenera](Unsorted/birational%20geometry.md) - [ ] [irregularity](Unsorted/birational%20geometry.md). Irregular are easier, but lose the Albanese and you know less about the geometry.4 - [ ] [Kodaira dimension](Unsorted/Enriques-Kodaira%20Classification.md). 1 and 2 are easy, 0 and $-\infty$ are more difficult (for surfaces). - [ ] Semiabelian varieties - [ ] Quasiprojective varieties - [ ] Universal property of the [Albanese](Albanese) variety. - [ ] Elliptic [K3 surfaces](K3%20surfaces.md), $X\to \PP^1$ fibers of type $IV^*, F_1, F_2, F_3$. - [ ] [dominant](Unsorted/dominant%20morphism.md) morphisms - [ ] [finite morphism](finite%20morphism) - [ ] Log-ramification formula. # Misc Complete curves and smooth complete surfaces are always projective: ![](attachments/Pasted%20image%2020220928221007.png) A Picard group with torsion: ![](attachments/Pasted%20image%2020220928231601.png)