Timeline for Isomorphic schemes over DVR
Current License: CC BY-SA 3.0
3 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 27, 2016 at 9:08 | comment | added | Philip Engel | True. Equivalently, the family must be chosen so that $C$ does not admit a first order thickening over $\textrm{Spec}\,\mathbb{C}[[t]]$, i.e. should be transverse to the locus of K3s with a $-2$-curve. | |
| Nov 27, 2016 at 8:58 | comment | added | Will Sawin | Specifically you need the normal bundle of $C$, which lies in an exact sequence $\mathcal O_C(-2) \to N_C \to \mathcal O_C$, to be $\mathcal O_C(-1) + \mathcal O_C(-1)$ and not $\mathcal O_C(-2) + \mathcal O_C$ to perform the flop, right? | |
| Nov 27, 2016 at 8:31 | history | answered | Philip Engel | CC BY-SA 3.0 |