Weighted Syzygies Library

Betti tables of weighted projective embeddings

This website, inspired by Juliette Bruce’s SyzygyData, is a tool for visualizing syzygies of strictly ample embeddings into weighted projective spaces. For now, everything is based on the paper Weighted Syzygies of Pointed Curves by Maya Banks, John Cobb, and Mahrud Sayrafi.


How does the complexity of syzygies of weighted embeddings by $|\mathcal{O}(dP)|$ change as $d$ grows?

See here for an explainer of this website, please get in touch with us if you’d like to use the Macaulay2 package used for these computations.

Weierstrass semigroups and embeddings of pointed curves

The number of genus $g$ Weierstrass semigroups per genus are bounded. Click on each genus to view the syzygy bounds.

genus $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
count 2 4 7 12 23 39 67 118 204

Example: a genus-4 complete intersection of a quadric and a cubic in $\PP^3$

This site collects Betti tables for section rings of pointed curves, organized by their Weierstrass semigroups. The tables describe the minimal free resolutions of weighted projective embeddings of the form $C \hookrightarrow \PP(w_0,\ldots,w_r)$.

The current example is a genus $4$ complete intersection with semigroup $H(P)=\langle 5,6,7,8,9 \rangle$. The generator records above each table are the weighted degrees and pole orders of the sections.

d =1 w =(1, 5, 6, 7, 8, 9) ord =(0, 5, 6, 7, 8, 9)
01234
total 11020154
0 1 empty empty empty empty
1 empty empty empty empty empty
2 empty empty empty empty empty
3 empty empty empty empty empty
4 empty empty empty empty empty
5 empty empty empty empty empty
6 empty empty empty empty empty
7 empty empty empty empty empty
8 empty empty empty empty empty
9 empty empty empty empty empty
10 empty empty empty empty empty
11 empty 1 empty empty empty
12 empty 1 empty empty empty
13 empty 2 empty empty empty
14 empty 2 empty empty empty
15 empty 2 empty empty empty
16 empty 1 empty empty empty
17 empty 1 1 empty empty
18 empty empty 2 empty empty
19 empty empty 3 empty empty
20 empty empty 4 empty empty
21 empty empty 4 empty empty
22 empty empty 3 empty empty
23 empty empty 2 empty empty
24 empty empty 1 1 empty
25 empty empty empty 2 empty
26 empty empty empty 3 empty
27 empty empty empty 3 empty
28 empty empty empty 3 empty
29 empty empty empty 2 empty
30 empty empty empty 1 empty
31 empty empty empty empty empty
32 empty empty empty empty 1
33 empty empty empty empty 1
34 empty empty empty empty 1
35 empty empty empty empty 1
36 empty empty empty empty empty
d =2 w =(1, 3, 3, 4, 4, 5, 5) ord =(0, 5, 6, 7, 8, 9, 10)
012345
total 1154045245
0 1 empty empty empty empty empty
1 empty empty empty empty empty empty
2 empty empty empty empty empty empty
3 empty empty empty empty empty empty
4 empty empty empty empty empty empty
5 empty 1 empty empty empty empty
6 empty 2 empty empty empty empty
7 empty 5 empty empty empty empty
8 empty 4 2 empty empty empty
9 empty 3 6 empty empty empty
10 empty empty 10 empty empty empty
11 empty empty 12 1 empty empty
12 empty empty 8 6 empty empty
13 empty empty 2 11 empty empty
14 empty empty empty 14 empty empty
15 empty empty empty 9 2 empty
16 empty empty empty 4 6 empty
17 empty empty empty empty 8 empty
18 empty empty empty empty 6 empty
19 empty empty empty empty 2 1
20 empty empty empty empty empty 2
21 empty empty empty empty empty 2
22 empty empty empty empty empty empty
d =3 w =(1, 2, 2, 3, 3, 3) ord =(0, 5, 6, 7, 8, 9)
01234
total 11020154
0 1 empty empty empty empty
1 empty empty empty empty empty
2 empty empty empty empty empty
3 empty empty empty empty empty
4 empty 3 empty empty empty
5 empty 7 empty empty empty
6 empty empty 9 empty empty
7 empty empty 11 empty empty
8 empty empty empty 9 empty
9 empty empty empty 6 empty
10 empty empty empty empty 3
11 empty empty empty empty 1
12 empty empty empty empty empty
d =4 w =(1, 2, 2, 2, 2, 3, 3, 3, 3) ord =(0, 5, 6, 7, 8, 9, 10, 11, 12)
01234567
total 128112210224140487
0 1 empty empty empty empty empty empty empty
1 empty empty empty empty empty empty empty empty
2 empty empty empty empty empty empty empty empty
3 empty 6 empty empty empty empty empty empty
4 empty 12 8 empty empty empty empty empty
5 empty 10 36 3 empty empty empty empty
6 empty empty 48 36 empty empty empty empty
7 empty empty 20 84 12 empty empty empty
8 empty empty empty 72 64 empty empty empty
9 empty empty empty 15 96 18 empty empty
10 empty empty empty empty 48 56 empty empty
11 empty empty empty empty 4 54 12 empty
12 empty empty empty empty empty 12 24 empty
13 empty empty empty empty empty empty 12 3
14 empty empty empty empty empty empty empty 4
15 empty empty empty empty empty empty empty empty
d =5 w =(1, 1, 2, 2, 2, 2) ord =(0, 5, 6, 7, 8, 9)
01234
total 11020154
0 1 empty empty empty empty
1 empty empty empty empty empty
2 empty empty empty empty empty
3 empty 10 empty empty empty
4 empty empty 20 empty empty
5 empty empty empty 15 empty
6 empty empty empty empty 4
7 empty empty empty empty empty
d =6 w =(1, 1, 1, 2, 2, 2) ord =(0, 5, 6, 7, 8, 9)
01234
total 11020154
0 1 empty empty empty empty
1 empty empty empty empty empty
2 empty 4 empty empty empty
3 empty 6 12 empty empty
4 empty empty 8 12 empty
5 empty empty empty 3 4
6 empty empty empty empty empty
d =7 w =(1, 1, 1, 1, 2) ord =(0, 5, 6, 7, 8)
0123
total 17104
0 1 empty empty empty
1 empty empty empty empty
2 empty 6 4 empty
3 empty 1 6 4
4 empty empty empty empty
d =8 w =(1, 1, 1, 1, 1) ord =(0, 5, 6, 7, 8)
0123
total 1694
0 1 empty empty empty
1 empty 2 empty empty
2 empty 4 9 4
3 empty empty empty empty
d =9 w =(1, 1, 1, 1, 1, 1) ord =(0, 5, 6, 7, 8, 9)
01234
total 1613124
0 1 empty empty empty empty
1 empty 6 4 empty empty
2 empty empty 9 12 4
3 empty empty empty empty empty

TODO

  • Visualize Kunz cone?
  • Display weighted $N_p$ conditions as a different colored shade?