Impact
~74k
people reached
- 0 posts edited
- 0 helpful flags
- 33 votes cast
Feb
1 |
comment |
Definition of ind-schemes
OK, I wrote down the details for myself... you're right. Sorry. |
Feb
1 |
comment |
Definition of ind-schemes
@Martin: I don't think so. In fact, if you restrict to quasi-compact schemes and coverings formed by finite (flat, jointly surjective etc.) families then the inductive limit presheaf is a sheaf. Therefore the map from the presheaf to the sheaf is an isomorphism when evaluated on qc schemes. It is not really a question of glueing things and covering the intersections with affines etc. |
Feb
1 |
comment |
Definition of ind-schemes
The equality $\text{Hom}(Y,\varinjlim X_n)=\varinjlim \text{Hom}(Y,X_n)$ extends quite easily from affine schemes $Y$ to quasi-compact ones. Away from qc schemes, I do not think it works. |
Jan
31 |
answered | A technical question about affine grassmanian |
Jan
31 |
comment |
A technical question about affine grassmanian
You're welcome! |
Jan
30 |
comment |
A technical question about affine grassmanian
I think you can find more details in Martin Kreidl's thesis, available at uni-due.de/~hx0051/Dissertation.pdf. Best, |
Jan
26 |
awarded | Necromancer |
Jan
24 |
awarded | Revival |
Jan
24 |
comment |
Flat cohomology for finite infinitesimal group scheme over a perfect field
"some more argument seems to be needed to explain why $X^{perf}$ is a $G^{perf}$-torsor" : perfectization commutes with products, so if the map $G\times X \to X\times X$ is an isomorphism then $G^{perf}\times X^{perf} \to X^{perf}\times X^{perf}$ also. |
Jan
24 |
answered | Flat cohomology for finite infinitesimal group scheme over a perfect field |
Jan
3 |
comment |
Nisnevich topology on non-(locally) Noetherian schemes
"the guy who asked", or "the girl who asked". After all, MO is for female mathematicians also. |
Jan
2 |
revised |
Descent of functions along finite birational morphisms
added 306 characters in body |
Jan
1 |
revised |
Pushing-forward morphisms
added 5 characters in body |
Dec
31 |
revised |
Pushing-forward morphisms
added 16 characters in body |
Dec
31 |
revised |
Pushing-forward morphisms
I realized the claim is not true in general. I provide explanations, a counter-example and examples where the claim still holds. |
Dec
25 |
comment |
Is the realtive dualizing sheaf Cohen-Macaulay?
I seemed to remember that CM-ification is problematic in general: which existence result(s) do you have in mind (if any) ? |
Dec
4 |
answered | Completion of a local ring of a curve |
Dec
4 |
revised |
Pushing-forward morphisms
added 5 characters in body |
Dec
3 |
answered | Pushing-forward morphisms |
Nov
16 |
comment |
Open affine subscheme of affine scheme which is not principal
I agree it is not clear why $D(X,Y)$ is not principal. Also the role of $U$ and $V$ is not clear: can you take $U=V=1$ ? |