Timeline for A-valued points of projective space
Current License: CC BY-SA 2.5
12 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 24, 2021 at 10:15 | comment | added | Watson | See also math.stackexchange.com/questions/1064778/… | |
| Oct 30, 2018 at 18:53 | comment | added | Watson | Exercise 3.19 in Görtz–Wedhorn (suitably modified as indicated in this erratum) requires the ring $A$ to be local, at least. | |
| S Nov 16, 2010 at 13:57 | vote | accept | C S | ||
| S Nov 16, 2010 at 13:57 | vote | accept | C S | ||
| S Nov 16, 2010 at 13:57 | |||||
| Nov 16, 2010 at 13:56 | answer | added | C S | timeline score: 1 | |
| Nov 16, 2010 at 9:24 | vote | accept | C S | ||
| S Nov 16, 2010 at 13:57 | |||||
| Nov 16, 2010 at 9:24 | vote | accept | C S | ||
| Nov 16, 2010 at 9:24 | |||||
| Nov 16, 2010 at 2:20 | answer | added | VA. | timeline score: 12 | |
| Nov 15, 2010 at 19:05 | comment | added | Dave Anderson | A warning tangentially relevant to the question: around the same part of that book, they attempt to define Proj(F) for a coherent sheaf F in terms of "prime ideal sheaves." There's some fishy stuff going on there, and I think the lesson is that one should not try to define things that way: read Hartshorne (or EGA) for this instead. | |
| Nov 15, 2010 at 18:03 | answer | added | user10849 | timeline score: 3 | |
| Nov 15, 2010 at 15:01 | comment | added | BCnrd | Yes, non-trivial line bundles on Spec($A$) which admit $n+1$ generators provide "additional" Spec($A$)-valued points of projective $n$-space $\mathbf{P}^n_{\mathbf{Z}}$. The same issue comes up when describing $C^{\infty}$-maps from smooth manifolds to real projective $n$-space (using $C^{\infty}$-line bundles), holomorphic maps from complex manifolds to complex projective $n$-space (using holomorphic line bundles), and continuous maps from topological spaces to real (resp. complex) projective $n$-space (using real (resp. complex) topological line bundles), so it's not specific to schemes. | |
| Nov 15, 2010 at 14:52 | history | asked | C S | CC BY-SA 2.5 |