Timeline for relations between 4 plane conics
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 2, 2017 at 22:13 | vote | accept | Dima Pasechnik | ||
| Jul 25, 2017 at 13:18 | comment | added | Dima Pasechnik | By "good" I meant "explicit", say, like Koszul ones, sorry. | |
| Jul 25, 2017 at 13:11 | answer | added | Robert Bryant | timeline score: 4 | |
| Jul 25, 2017 at 12:51 | comment | added | Jason Starr | What do you mean by a "good description"? For a $3$-dimensional vector space $V$, the kernel $K(V)$ of the map $\text{Sym}^2(\text{Sym}^2(V))\to \text{Sym}^4(V)$ is a representation of $\textbf{GL}(V)$ that can be explicitly described via Schur functors. For a $4$-dimensional subspace $U$ of $\text{Sym}^2(V)$ with $2$-dimensional quotient $W$, there is an induced surjection $T_W:K(V)\to \text{Sym}^2(W)$. The $3$-dimensional space you describe is the kernel of $T_W$. | |
| Jul 25, 2017 at 11:16 | history | asked | Dima Pasechnik | CC BY-SA 3.0 |