It’s still unknown whether there are infinitely many number fields of class number 1.
So I decided to investigate more number fields uncovered in the Wikipedia article.
Littlewood Polynomials , i.e. where is a Littlewood polynomial.
Conjecture: There exists , such that for sufficiently large degree, the probability for a randomly-chosen Littlewood polynomial to generate a class-1 field is larger than .
The way to randomly choose Littlewood polynomials is up to interpretation: it’s not sure how one could avoid reducible polynomials.
Computational results:
Degree | Number of fields with class number > 1 |
---|---|
≤9 | 0 |
10 | 2 |
11 | 0 |
12 | 4 |
13 | 8 |
14 | 45 |
15 | 46 |
16 | 135 |
17 | 212 |
18 | 452 |
19 | 766 |
20 | 1122 |
*Different Littlewood polynomials could generate the same field, e.g. and , so there’s a difference between counting the number of polynomials and the number of fields.
.
(Requires xn+x+1 to be reducible, i.e. x≠2 mod 3 unless x=2)
All computed cases have class number 1. The s in the cases are up to 70 except 69.
Remark: To compute the class number, one can use the Dedekind L function(hard, since the field is generally non-abelian) and the regulator.
An empirical formula for the regulator: .
Computational results:
n | REGULATOR | Class number |
---|---|---|
2 | 1 | 1 |
3 | 0.382245085840036 | 1 |
4 | 0.337377803571562 | 1 |
6 | 0.658529208858349 | 1 |
7 | 1.28891714323854 | 1 |
9 | 4.58756375116217 | 1 |
10 | 7.34813790494827 | 1 |
12 | 43.0124997055349 | 1 |
13 | 117.917198365552 | 1 |
15 | 548.874139448263 | 1 |
16 | 1339.39466430348 | 1 |
18 | 9114.45867514349 | 1 |
19 | 40842.9289743928 | 1 |
21 | 312816.6014877311 | 1 |
22 | 685583.0462776966 | 1 |
24 | 9163307.175032053 | 1 |
25 | 36955124.38960424 | 1 |
27 | 314436524.8339556 | 1 |
28 | 832511028.3094091 | 1 |
30 | 11086740597.223595 | 1 |
31 | 60402933903.83712 | 1 |
33 | 794597544869.8735 | 1 |
34 | 1946991838336.107 | 1 |
36 | 42496810214502.4 | 1 |
37 | 232694775426930.7 | 1 |
39 | 1954406735071007.5 | 1 |
40 | 9483736502678452.0 | 1 |
42 | 1.22671527299859e17 | 1 |
43 | 8.65244826944888e17 | 1 |
45 | 1.81327874783812e19 | 1 |
46 | 5.12503081683112e19 | 1 |
48 | 1.44282942692530e21 | 1 |
49 | 8.96333031274895e21 | 1 |
51 | 1.39007666627654e23 | 1 |
52 | 5.53110242701541e23 | 1 |
54 | 1.37500354842092e25 | 1 |
55 | 5.98268106963661e25 | 1 |
57 | 2.10334315815568e27 | 1 |
58 | 7.03923877738823e27 | 1 |
60 | 2.40946814771980e29 | 1 |
61 | 1.45431932648604e30 | 1 |
63 | 2.90399143790153e31 | 1 |
64 | 1.36851987479281e32 | 1 |
66 | 3.34395953400078e33 | 1 |
67 | 2.38125833961797e34 | 1 |
69 | ? | ? |
70 | 2.97700584009327e36 | 1 |