Fanography

A tool to visually study the geography of Fano 3-folds.

Toric Fano threefolds

The table lists the 18 smooth toric Fano threefolds. The diagrams use the lattice vertices in the corresponding Graded Ring Database records; each row links directly to its record. Drag a diagram to rotate the polytope.

ID$\rho$$g$indexGRDBpolytopedescription
1-171334#23

projective space $\mathbb{P}^3$

2-362321#7

$\mathbb{P}(\mathcal{O}_{\mathbb{P}^2}\oplus\mathcal{O}_{\mathbb{P}^2}(2))$

2-352292#20

$\mathrm{Bl}_p\mathbb{P}^3$

alternative
$\mathbb{P}(\mathcal{O}_{\mathbb{P}^2}\oplus\mathcal{O}_{\mathbb{P}^2}(1))$
2-332281#19

blowup of 1-17 in a line

2-342281#22

$\mathbb{P}^1\times\mathbb{P}^2$

3-313271#11

blowup of the cone over a smooth quadric in $\mathbb{P}^3$ in the vertex

alternative
$\mathbb{P}(\mathcal{O}\oplus\mathcal{O}(1,1))$ over $\mathbb{P}^1\times\mathbb{P}^1$
3-293261#6

blowup of 2-35 in a line on the exceptional divisor

3-303261#12

blowup of 2-35 in the proper transform of a line containing the center of the blowup

alternative
$\mathbb{P}_{\mathbb{F}_1}(\mathcal{O}\oplus\mathcal{O}(\ell))$ where $\ell^2=1$
3-273252#21

$\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^1$

3-283251#17

$\mathbb{P}^1\times\mathrm{Bl}_p\mathbb{P}^2$

3-263241#16

blowup of 1-17 in the disjoint union of a point and a line

alternative
blowup of line on a plane which is section of 2-34 mapping to $\mathbb{P}^2$
4-124241#8

blowup of 2-33 in the disjoint union of two exceptional lines of the blowup

3-253231#18

blowup of 1-17 in the disjoint union of two lines

alternative
$\mathbb{P}(\mathcal{O}(1,0)\oplus\mathcal{O}(0,1))$ over $\mathbb{P}^1\times\mathbb{P}^1$
4-114231#10

blowup of 3-28 in $\{x\}\times E$, $x\in\mathbb{P}^1$ and $E$ the $(-1)$-curve

4-104221#14

$\mathbb{P}^1\times\mathrm{Bl}_2\mathbb{P}^2$

4-94211#13

blowup of 3-25 in an exceptional curve of the blowup

5-25191#9

blowup of 3-25 in the disjoint union of two exceptional lines on the same irreducible component

5-35191#15

$\mathbb{P}^1\times\mathrm{Bl}_3\mathbb{P}^2$