Timeline for Deligne-Rapoport stack and reduction mod p of X0(p)
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 9, 2014 at 10:49 | comment | added | user27920 | @NadimRustom: see section B.2.2 of the preprint uni-due.de/~ade847f/bdp5 | |
| Dec 9, 2013 at 23:04 | comment | added | David Zureick-Brown | @NadimRustom: You can also have D1-D2 on a usual curve with degree 1 but no sections (i.e., not equivalent to an effective divisor). | |
| Oct 8, 2013 at 11:21 | comment | added | Nadim Rustom | @DavidLoeffler: Thanks, yes that sounds quite reasonable. I just found it surprising that on stacks, an invertible sheaf can have positive degree without having global sections. | |
| Oct 8, 2013 at 11:02 | history | edited | Olivier | CC BY-SA 3.0 |
Corrected grammar
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| Oct 8, 2013 at 10:05 | comment | added | David Loeffler | If the degree of $\omega$ weren't strictly positive, then not only would there be no weight 1 cusp forms for $\Gamma_0(1)$, but there would be no weight 1 cusp forms for any level whatsoever, because pullback via a finite flat morphism will just multiply the degree of $\omega$ by a positive constant. Does that answer your (1)? | |
| Oct 8, 2013 at 8:25 | history | asked | Nadim Rustom | CC BY-SA 3.0 |