Fanography

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

This table tries to give the state of the art of the ongoing project of understanding K-stability for all Fano 3-folds. Let me know if I have made a mistake, or am missing some recent progress!

Below the table we provide an overview of the open cases.

ID description moduli $\mathrm{Aut}^0$ K‑stability K‑polystability K‑semistability references
1-1

double cover of $\mathbb{P}^3$ with branch locus a divisor of degree 6

alternative
hypersurface of degree 6 in $\mathbb{P}(1,1,1,1,3)$

68

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-2
  1. hypersurface of degree 4 in $\mathbb{P}^4$
  2. double cover of 1-16 with branch locus a divisor of degree 8
  1. 45
  2. 44

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-3

complete intersection of quadric and cubic in $\mathbb{P}^5$

34

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-4

complete intersection of 3 quadrics in $\mathbb{P}^6$

27

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-5 Gushel–Mukai 3-fold
  1. section of Plücker embedding of $\mathrm{Gr}(2,5)$ by codimension 2 subspace and a quadric
  2. double cover of 1-15 with branch locus an anticanonical divisor
  1. 22
  2. 19

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-6

section of half-spinor embedding of a connected component of $\mathrm{OGr}_+(5,10)$ by codimension 7 subspace

18

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-7

section of Plücker embedding of $\mathrm{Gr}(2,6)$ by codimension 5 subspace

15

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-8

section of Plücker embedding of $\mathrm{SGr}(3,6)$ by codimension 3 subspace

12

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-9

section of the adjoint $\mathrm{G}_2$-Grassmannian $\mathrm{G}_2\mathrm{Gr}(2,7)$ by codimension 2 subspace

10

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
1-10

zero locus of $(\bigwedge^2\mathcal{U}^\vee)^{\oplus 3}$ on $\mathrm{Gr}(3,7)$

6

$\mathrm{Aut}^0(X)$ moduli
$\mathrm{PGL}_2$ 0
$\mathbb{G}_{\mathrm{a}}$ 0
$\mathbb{G}_{\mathrm{m}}$ 1
general member is K‑stable but there exists one that is not general member is K‑polystable but there exists one that is not general member is K‑semistable
1-11

hypersurface of degree 6 in $\mathbb{P}(1,1,1,2,3)$

34

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-12

double cover of $\mathbb{P}^3$ with branch locus a smooth quartic surface

alternative
hypersurface of degree 4 in $\mathbb{P}(1,1,1,1,2)$

19

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-13

hypersurface of degree 3 in $\mathbb{P}^4$

10

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-14

complete intersection of 2 quadrics in $\mathbb{P}^5$

3

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
1-15

section of Plücker embedding of $\mathrm{Gr}(2,5)$ by codimension 3 subspace

0

$\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
1-16

hypersurface of degree 2 in $\mathbb{P}^4$

0

$\mathrm{PSO}_5$

none are K-stable every member is K‑polystable every member is K‑semistable
1-17

projective space $\mathbb{P}^3$

0

$\mathrm{PGL}_4$

none are K-stable every member is K‑polystable every member is K‑semistable
2-1

blowup of 1-11 in an elliptic curve which is the intersection of two divisors from half the anticanonical linear system

36

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
2-2

double cover of 2-34 with branch locus a $(2,4)$-divisor

33

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
2-3

blowup of 1-12 in an elliptic curve which is the intersection of two divisors from half the anticanonical linear system

23

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
2-4

blowup of 1-17 in the intersection of two cubics

alternative
$(1,3)$-divisor on $\mathbb{P}^1\times\mathbb{P}^3$

21

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
2-5

blowup of 1-13 in a plane cubic

16

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
2-6 Verra 3-fold
  1. $(2,2)$-divisor on $\mathbb{P}^2\times\mathbb{P}^2$
  2. double cover of 2-32 with branch locus an anticanonical divisor
  1. 19
  2. 18

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
2-7

blowup of 1-16 in the intersection of two divisors from $|\mathcal{O}_Q(2)|$

14

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
2-8
  1. double cover of 2-35 with branch locus an anticanonical divisor such that the intersection with the exceptional divisor is smooth
  2. double cover of 2-35 with branch locus an anticanonical divisor such that the intersection with the exceptional divisor is singular but reduced
  1. 18
  2. 17

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
2-9

complete intersection of degree $(1,1)$ and $(2,1)$ in $\mathbb{P}^3\times\mathbb{P}^2$

alternative
blowup of 1-17 in a curve of degree 7 and genus 5, which is an intersection of 3 cubics

13

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
2-10

blowup of 1-14 in an elliptic curve which is an intersection of 2 hyperplanes

11

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
2-11

blowup of 1-13 in a line

12

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
2-12

intersection of 3 $(1,1)$-divisors in $\mathbb{P}^3\times\mathbb{P}^3$

alternative
blowup of 1-17 in a curve of degree 6 and genus 3 which is an intersection of 4 cubics

9

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
2-13

blowup of 1-16 in a curve of degree 6 and genus 2

8

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
2-14

blowup of 1-15 in an elliptic curve which is an intersection of 2 hyperplanes

7

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
2-15
  1. blowup of 1-17 in the intersection of a quadric and a cubic where the quadric is smooth
  2. blowup of 1-17 in the intersection of a quadric and a cubic where the quadric is singular but reduced
  1. 9
  2. 8

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
2-16

blowup of 1-14 in a conic

7

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
2-17

blowup of 1-16 in an elliptic curve of degree 5

5

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
2-18

double cover of 2-34 with branch locus a divisor of degree $(2,2)$

6

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
2-19

blowup of 1-14 in a line

5

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
2-20

blowup of 1-15 in a twisted cubic

3

$\mathrm{Aut}^0(X)$ moduli
$\mathbb{G}_{\mathrm{m}}$ 0
general member is K‑stable but there exists one that is not general member is K‑polystable but there exists one that is not general member is K‑semistable
2-21

blowup of 1-16 in a twisted quartic

2

$\mathrm{Aut}^0(X)$ moduli
$\mathrm{PGL}_2$ 0
$\mathbb{G}_{\mathrm{a}}$ 0
$\mathbb{G}_{\mathrm{m}}$ 1
general member is K‑stable but there exists one that is not general member is K‑polystable but there exists one that is not general member is K‑semistable
2-22

blowup of 1-15 in a conic

1

$\mathrm{Aut}^0(X)$ moduli
$\mathbb{G}_{\mathrm{m}}$ 0
general member is K‑stable but there exists one that is not general member is K‑polystable but there exists one that is not every member is K‑semistable
2-23
  1. blowup of 1-16 in an intersection of $A\in|\mathcal{O}_Q(1)|$ and $B\in|\mathcal{O}_Q(2)|$ such that $A$ is smooth
  2. blowup of 1-16 in an intersection of $A\in|\mathcal{O}_Q(1)|$ and $B\in|\mathcal{O}_Q(2)|$ such that $A$ is singular
  1. 2
  2. 1

$0$

none are K-stable none are K-polystable none are K-semistable
2-24

divisor on $\mathbb{P}^2\times\mathbb{P}^2$ of bidegree $(1,2)$

1

$\mathrm{Aut}^0(X)$ moduli
$\mathbb{G}_{\mathrm{m}}^2$ 0
$\mathbb{G}_{\mathrm{m}}$ 0
general member is K‑stable but there exists one that is not general member is K‑polystable but there exists one that is not general member is K‑semistable
2-25

blowup of 1-17 in an elliptic curve which is an intersection of 2 quadrics

alternative
$(1,2)$-divisor on $\mathbb{P}^1\times\mathbb{P}^3$

1

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
2-26

blowup of 1-15 in a line

0

$\mathrm{Aut}^0(X)$ moduli
$\mathrm{B}$ 0
$\mathbb{G}_{\mathrm{m}}$ 0
none are K-stable none are K-polystable general member is K‑semistable but there exists one that is not
2-27

blowup of 1-17 in a twisted cubic

0

$\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
2-28

blowup of 1-17 in a plane cubic

1

$\mathbb{G}_{\mathrm{a}}^3\rtimes\mathbb{G}_{\mathrm{m}}$

none are K-stable none are K-polystable none are K-semistable
2-29

blowup of 1-16 in a conic

0

$\mathbb{G}_{\mathrm{m}}\times\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
2-30

blowup of 1-17 in a conic

0

$\mathrm{PSO}_{5;1}$

none are K-stable none are K-polystable none are K-semistable
2-31

blowup of 1-16 in a line

0

$\mathrm{PSO}_{5;2}$

none are K-stable none are K-polystable none are K-semistable
2-32

divisor on $\mathbb{P}^2\times\mathbb{P}^2$ of bidegree $(1,1)$

alternative
$\mathbb{P}(\mathrm{T}_{\mathbb{P}^2})$
the complete flag variety for $\mathbb{P}^2$

0

$\mathrm{PGL}_3$

none are K-stable every member is K‑polystable every member is K‑semistable
2-33

blowup of 1-17 in a line

0

$\mathrm{PGL}_{4;2}$

none are K-stable none are K-polystable none are K-semistable
2-34

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

0

$\mathrm{PGL}_2\times\mathrm{PGL}_3$

none are K-stable every member is K‑polystable every member is K‑semistable
2-35

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

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

0

$\mathrm{PGL}_{4;1}$

none are K-stable none are K-polystable none are K-semistable
2-36

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

0

$\mathrm{Aut}(\mathbb{P}(1,1,1,2))$

none are K-stable none are K-polystable none are K-semistable
3-1

double cover of 3-27 with branch locus a divisor of degree $(2,2,2)$

17

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
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 $Y\in|\mathcal{L}|$

11

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
3-3

divisor on $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^2$ of degree $(1,1,2)$

9

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
3-4

blowup of 2-18 in a smooth fiber of the composition of the projection to $\mathbb{P}^1\times\mathbb{P}^2$ with the projection to $\mathbb{P}^2$ of the double cover with the projection

8

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
3-5

blowup of 2-34 in a curve $C$ of degree $(5,2)$ such that $C\hookrightarrow\mathbb{P}^1\times\mathbb{P}^2\to\mathbb{P}^2$ is an embedding

5

$\mathrm{Aut}^0(X)$ moduli
$\mathbb{G}_{\mathrm{m}}$ 0
general member is K‑stable but there exists one that is not general member is K‑polystable but there exists one that is not general member is K‑semistable
3-6

blowup of 1-17 in the disjoint union of a line and an elliptic curve of degree 4

alternative
complete intersection of degree $(1,0,2)$ and $(0,1,1)$ in $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^3$

5

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
3-7

blowup of 2-32 in an elliptic curve which is the intersection of two divisors from $|-\frac{1}{2}\mathrm{K}_W|$

4

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
3-8

divisor from the linear system $|(\alpha\circ\pi_1)^*(\mathcal{O}_{\mathbb{P}^2}(1)\otimes\pi_2^*(\mathcal{O}_{\mathbb{P}^2}(2))|$ where $\pi_i\colon\mathrm{Bl}_1\mathbb{P}^2\times\mathbb{P}^2\to\mathrm{Bl}_1\mathbb{P}^2,\mathbb{P}^2$ are the projections, and $\alpha\colon\mathrm{Bl}_1\mathbb{P}^2\to\mathbb{P}^2$ is the blowup

3

$\mathrm{Aut}^0(X)$ moduli
$\mathbb{G}_{\mathrm{m}}$ 0
general member is K‑stable but there exists one that is not general member is K‑polystable but there exists one that is not general member is K‑semistable
3-9

blowup of the cone over the Veronese of $\mathbb{P}^2$ in $\mathbb{P}^5$ with center the disjoint union of the vertex and a quartic curve on $\mathbb{P}^2$

6

$\mathbb{G}_{\mathrm{m}}$

none are K-stable every member is K‑polystable every member is K‑semistable
3-10

blowup of 1-16 in the disjoint union of 2 conics

alternative
complete intersection of degree $(1,0,1)$, $(0,1,1)$ and $(0,0,2)$ in $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^4$

2

$\mathrm{Aut}^0(X)$ moduli
$\mathbb{G}_{\mathrm{m}}^2$ 0
$\mathbb{G}_{\mathrm{m}}$ 1
general member is K‑stable but there exists one that is not general member is K‑polystable but there exists one that is not every member is K‑semistable
3-11

blowup of 2-35 in an elliptic curve which is the intersection of two divisors from $|-\frac{1}{2}\mathrm{K}_{V_7}|$

2

$0$

general member is K‑stable general member is K‑polystable general member is K‑semistable
3-12

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

1

$\mathrm{Aut}^0(X)$ moduli
$\mathbb{G}_{\mathrm{m}}$ 0
general member is K‑stable but there exists one that is not general member is K‑polystable but there exists one that is not every member is K‑semistable
3-13

blowup of 2-32 in a curve $C$ of bidegree $(2,2)$ such that the composition $C\hookrightarrow W\hookrightarrow\mathbb{P}^2\times\mathbb{P}^2\overset{p_i}{\to}\mathbb{P}^2$ is an embedding for $i=1,2$

1

$\mathrm{Aut}^0(X)$ moduli
$\mathrm{PGL}_2$ 0
$\mathbb{G}_{\mathrm{a}}$ 0
$\mathbb{G}_{\mathrm{m}}$ 1
none are K-stable general member is K‑polystable but there exists one that is not every member is K‑semistable
3-14

blowup of 1-17 in the disjoint union of a plane cubic curve and a point outside the plane

1

$\mathbb{G}_{\mathrm{m}}$

none are K-stable none are K-polystable none are K-semistable
3-15

blowup of 1-16 in the disjoint union of a line and a conic

0

$\mathbb{G}_{\mathrm{m}}$

none are K-stable every member is K‑polystable every member is K‑semistable
3-16

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

0

$\mathrm{B}$

none are K-stable none are K-polystable none are K-semistable
3-17

divisor on $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^2$ of degree $(1,1,1)$

0

$\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
3-18

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

0

$\mathrm{B}\times\mathbb{G}_{\mathrm{m}}$

none are K-stable none are K-polystable none are K-semistable
3-19

blowup of 1-16 in two non-collinear points

0

$\mathbb{G}_{\mathrm{m}}\times\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
3-20

blowup of 1-16 in the disjoint union of two lines

0

$\mathbb{G}_{\mathrm{m}}\times\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
3-21

blowup of 2-34 in a curve of degree $(2,1)$

0

$\mathbb{G}_{\mathrm{a}}^2\rtimes\mathbb{G}_{\mathrm{m}}^2$

none are K-stable none are K-polystable none are K-semistable
3-22

blowup of 2-34 in a conic on $\{x\}\times\mathbb{P}^2$, $x\in\mathbb{P}^1$

0

$\mathrm{B}\times\mathrm{PGL}_2$

none are K-stable none are K-polystable none are K-semistable
3-23

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

0

$\mathbb{G}_{\mathrm{a}}^3\rtimes(\mathrm{B}\times\mathbb{G}_{\mathrm{m}})$

none are K-stable none are K-polystable none are K-semistable
3-24

the fiber product of 2-32 with $\mathrm{Bl}_p\mathbb{P}^2$ over $\mathbb{P}^2$

alternative
complete intersection of degree $(1,1,0)$ and $(0,1,1)$ in $\mathbb{P}^1\times\mathbb{P}^2\times\mathbb{P}^2$

0

$\mathrm{PGL}_{3;1}$

none are K-stable none are K-polystable none are K-semistable
3-25

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

alternative
$\mathbb{P}(\mathcal{O}(1,0)\oplus\mathcal{O}(0,1))$ over $\mathbb{P}^1\times\mathbb{P}^1$

0

$\mathrm{PGL}_{(2,2)}$

none are K-stable every member is K‑polystable every member is K‑semistable
3-26

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 $\mathbb{P}^2$

0

$\mathbb{G}_{\mathrm{a}}^3\rtimes(\mathrm{GL}_2\times\mathbb{G}_{\mathrm{m}})$

none are K-stable none are K-polystable none are K-semistable
3-27

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

0

$\mathrm{PGL}_2^3$

none are K-stable every member is K‑polystable every member is K‑semistable
3-28

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

0

$\mathrm{PGL}_2\times\mathrm{PGL}_{3;1}$

none are K-stable none are K-polystable none are K-semistable
3-29

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

0

$\mathrm{PGL}_{4;3,1}$

none are K-stable none are K-polystable none are K-semistable
3-30

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 $\ell^2=1$

0

$\mathrm{PGL}_{4;2,1}$

none are K-stable none are K-polystable none are K-semistable
3-31

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

0

$\mathrm{PSO}_{6;1}$

none are K-stable none are K-polystable none are K-semistable
4-1

divisor on $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^1$ of degree $(1,1,1,1)$

3

$0$

every member is K‑stable every member is K‑polystable every member is K‑semistable
4-2

blowup of the cone over a smooth quadric in $\mathbb{P}^3$ in the disjoint union of the vertex and an elliptic curve on the quadric

2

$\mathbb{G}_{\mathrm{m}}$

none are K-stable every member is K‑polystable every member is K‑semistable
4-3

blowup of 3-27 in a curve of degree $(1,1,2)$

0

$\mathbb{G}_{\mathrm{m}}$

none are K-stable every member is K‑polystable every member is K‑semistable
4-4

blowup of 3-19 in the proper transform of a conic through the points

0

$\mathbb{G}_{\mathrm{m}}^2$

none are K-stable every member is K‑polystable every member is K‑semistable
4-5

blowup of 2-34 in the disjoint union of a curve of degree $(2,1)$ and a curve of degree $(1,0)$

0

$\mathbb{G}_{\mathrm{m}}^2$

none are K-stable none are K-polystable none are K-semistable
4-6

blowup of 1-17 in the disjoint union of 3 lines

alternative
blowup of 3-27 in the tridiagonal

0

$\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
4-7

blowup of 2-32 in the disjoint union of a curve of degree $(0,1)$ and a curve of degree $(1,0)$

0

$\mathrm{GL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
4-8

blowup of 3-27 in a curve of degree $(0,1,1)$

0

$\mathrm{B}\times\mathrm{PGL}_2$

none are K-stable none are K-polystable none are K-semistable
4-9

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

0

$\mathrm{PGL}_{(2,2);1}$

none are K-stable none are K-polystable none are K-semistable
4-10

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

0

$\mathrm{PGL}_2\times\mathrm{B}^2$

none are K-stable none are K-polystable none are K-semistable
4-11

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

0

$\mathrm{B}\times\mathrm{PGL}_{3;1}$

none are K-stable none are K-polystable none are K-semistable
4-12

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

0

$\mathbb{G}_{\mathrm{a}}^4\rtimes(\mathrm{GL}_2\times\mathbb{G}_{\mathrm{m}})$

none are K-stable none are K-polystable none are K-semistable
4-13

blowup of 3-27 in a curve of degree $(1,1,3)$

1

$\mathrm{Aut}^0(X)$ moduli
$\mathbb{G}_{\mathrm{m}}$ 0
general member is K‑stable but there exists one that is not general member is K‑polystable but there exists one that is not general member is K‑semistable
5-1

blowup of 2-29 in the disjoint union of three exceptional lines of the blowup

0

$\mathbb{G}_{\mathrm{m}}$

none are K-stable every member is K‑polystable every member is K‑semistable
5-2

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

0

$\mathbb{G}_{\mathrm{m}}\times\mathrm{GL}_2$

none are K-stable none are K-polystable none are K-semistable
5-3

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

0

$\mathrm{PGL}_2\times\mathbb{G}_{\mathrm{m}}^2$

none are K-stable every member is K‑polystable every member is K‑semistable
6-1

$\mathbb{P}^1\times\mathrm{Bl}_4\mathbb{P}^2$

0

$\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
7-1

$\mathbb{P}^1\times\mathrm{Bl}_5\mathbb{P}^2$

2

$\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
8-1

$\mathbb{P}^1\times\mathrm{Bl}_6\mathbb{P}^2$

4

$\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
9-1

$\mathbb{P}^1\times\mathrm{Bl}_7\mathbb{P}^2$

6

$\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable
10-1

$\mathbb{P}^1\times\mathrm{Bl}_8\mathbb{P}^2$

8

$\mathrm{PGL}_2$

none are K-stable every member is K‑polystable every member is K‑semistable

Open cases

K-stability is not fully understood for the following families:

K-polystability is not fully understood for the following families:

K-semistability is not fully understood for the following families: