Fano variety 3-2
divisor from $|\mathcal{L}^{\otimes 2}\otimes\mathcal{O}(2,3)|$ on the $\mathbb{P}^2$-bundle $\mathbb{P}(\mathcal{O}\oplus\mathcal{O}(-1,-1)^{\oplus 2})$ over $\mathbb{P}^1\times\mathbb{P}^1$ such that $X\cap Y$ is irreducible, and $\mathcal{L}$ is the tautological bundle, and $Y\in|\mathcal{L}|$
- Picard rank
- 3 (others)
- $-\mathrm{K}_X^3$
- 14
- $\mathrm{h}^{1,2}(X)$
- 3
0 0
0 3 0
0 3 3 0
0 3 0
0 0
1
0 0
0 11 2
0 0 6 10
0 0 0
0 0
0
- index
- 1
- $\dim\mathrm{H}^0(X,\omega_X^\vee)$
- 10
- $-\mathrm{K}_X$ very ample?
- yes
- $-\mathrm{K}_X$ basepoint free?
- yes
- hyperelliptic
- no
- trigonal
- yes
This variety is rational.
This variety is primitive.
- number of moduli
- 11
- Bott vanishing
- does not hold
$\mathrm{Aut}^0(X)$ | $\dim\mathrm{Aut}^0(X)$ | number of moduli |
---|---|---|
$0$ | 0 | 11 |
There exist interesting semiorthogonal decompositions, but this data is not yet added.
By Hertling–Manin–Teleman we have that quantum cohomology cannot be generically semisimple, as $\mathrm{h}^{1,2}\neq 0$.
Fano 3-folds from homogeneous vector bundles over Grassmannians gives the following description(s):
- variety
- $\mathbb{P}^1 \times \mathbb{P}^1 \times \mathbb{P}^5$
- bundle
- $\Lambda(0,0,1) \oplus \mathcal{O}(0,1,2)$
See the big table for more information.
- general member is K‑stable
- general member is K‑polystable
- general member is K‑semistable