Timeline for Does a moving family of lines through a fixed point produce a singularity?
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 15, 2016 at 10:49 | vote | accept | Irfan Kadikoylu | ||
| Jul 8, 2016 at 16:40 | answer | added | abx | timeline score: 2 | |
| Jul 8, 2016 at 12:18 | comment | added | Lazzaro Campeotti | Just a comment: If $X$ is not a cone, the lines in $X$ through $p$ fill up at most a codimension-1 subset of $X$, hence $n$ is at most $r-3$. But for example there are smooth cubic threefolds in $\mathbf P^4$ with Eckardt points, i.e. points where the tangent hyperplane section is a cone (over a curve, ie $n=1$). So $n=r-3$ is not sufficient in general. | |
| Jul 8, 2016 at 11:34 | history | asked | Irfan Kadikoylu | CC BY-SA 3.0 |