Fanography

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

Identification

Fano variety 2-21

blowup of 1-16 in a twisted quartic

rank
2 (others)
$-\mathrm{K}_X^3$
28
$\mathrm{h}^{1,2}(X)$
0
Hodge diamond
1
0 0
0 2 0
0 0 0 0
0 2 0
0 0
1
Anticanonical bundle
index
1
$\dim\mathrm{H}^0(X,\omega_X^\vee)$
17
$-\mathrm{K}_X$ very ample?
yes
$-\mathrm{K}_X$ basepoint free?
yes
hyperelliptic
no
trigonal
no
Birational geometry

This variety is rational.


This variety is the blowup of

  • 1-16, in a curve of genus 0

This variety is fibre-like, i.e. it can appear as the fibre of a Mori fibre space.

Deformation theory
number of moduli
2

$\mathrm{Aut}^0(X)$ $\dim\mathrm{Aut}^0(X)$ number of moduli
$\mathrm{PGL}_2$ 3 0
$\mathbb{G}_{\mathrm{a}}$ 1 0
$\mathbb{G}_{\mathrm{m}}$ 1 1
$0$ 0 2