Properties

Label 20.0.52205008669...8677.1
Degree $20$
Signature $[0, 10]$
Discriminant $3^{10}\cdot 13^{5}\cdot 47^{8}$
Root discriminant $15.34$
Ramified primes $3, 13, 47$
Class number $1$
Class group Trivial
Galois group $D_4\times D_5$ (as 20T21)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, 0, -3, -2, 7, 18, 29, 41, 45, 22, 0, 1, 3, 0, -9, -2, 0, -1, 2, -2, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^20 - 2*x^19 + 2*x^18 - x^17 - 2*x^15 - 9*x^14 + 3*x^12 + x^11 + 22*x^9 + 45*x^8 + 41*x^7 + 29*x^6 + 18*x^5 + 7*x^4 - 2*x^3 - 3*x^2 + 1)
 
gp: K = bnfinit(x^20 - 2*x^19 + 2*x^18 - x^17 - 2*x^15 - 9*x^14 + 3*x^12 + x^11 + 22*x^9 + 45*x^8 + 41*x^7 + 29*x^6 + 18*x^5 + 7*x^4 - 2*x^3 - 3*x^2 + 1, 1)
 

Normalized defining polynomial

\( x^{20} - 2 x^{19} + 2 x^{18} - x^{17} - 2 x^{15} - 9 x^{14} + 3 x^{12} + x^{11} + 22 x^{9} + 45 x^{8} + 41 x^{7} + 29 x^{6} + 18 x^{5} + 7 x^{4} - 2 x^{3} - 3 x^{2} + 1 \)

magma: DefiningPolynomial(K);
 
sage: K.defining_polynomial()
 
gp: K.pol
 

Invariants

Degree:  $20$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[0, 10]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(522050086690675147528677=3^{10}\cdot 13^{5}\cdot 47^{8}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $15.34$
magma: Abs(Discriminant(Integers(K)))^(1/Degree(K));
 
sage: (K.disc().abs())^(1./K.degree())
 
gp: abs(K.disc)^(1/poldegree(K.pol))
 
Ramified primes:  $3, 13, 47$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is not Galois over $\Q$.
This is not a CM field.

Integral basis (with respect to field generator \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $a^{16}$, $a^{17}$, $\frac{1}{2327} a^{18} + \frac{606}{2327} a^{17} - \frac{392}{2327} a^{16} + \frac{750}{2327} a^{15} + \frac{154}{2327} a^{14} + \frac{483}{2327} a^{13} + \frac{855}{2327} a^{12} + \frac{699}{2327} a^{11} - \frac{1062}{2327} a^{10} + \frac{618}{2327} a^{9} + \frac{410}{2327} a^{8} - \frac{431}{2327} a^{7} + \frac{477}{2327} a^{6} + \frac{83}{179} a^{5} - \frac{298}{2327} a^{4} - \frac{349}{2327} a^{3} + \frac{970}{2327} a^{2} - \frac{428}{2327} a - \frac{93}{2327}$, $\frac{1}{44624879} a^{19} - \frac{5828}{44624879} a^{18} - \frac{7966992}{44624879} a^{17} - \frac{6701350}{44624879} a^{16} + \frac{6341927}{44624879} a^{15} + \frac{1629331}{3432683} a^{14} + \frac{304615}{44624879} a^{13} + \frac{22197910}{44624879} a^{12} - \frac{10734788}{44624879} a^{11} - \frac{7384444}{44624879} a^{10} - \frac{12222690}{44624879} a^{9} + \frac{8009981}{44624879} a^{8} + \frac{4474568}{44624879} a^{7} - \frac{13062404}{44624879} a^{6} + \frac{11813036}{44624879} a^{5} + \frac{5768168}{44624879} a^{4} - \frac{5344238}{44624879} a^{3} - \frac{19193490}{44624879} a^{2} - \frac{18703608}{44624879} a - \frac{3781052}{44624879}$

magma: IntegralBasis(K);
 
sage: K.integral_basis()
 
gp: K.zk
 

Class group and class number

Trivial group, which has order $1$

magma: ClassGroup(K);
 
sage: K.class_group().invariants()
 
gp: K.clgp
 

Unit group

magma: UK, f := UnitGroup(K);
 
sage: UK = K.unit_group()
 
Rank:  $9$
magma: UnitRank(K);
 
sage: UK.rank()
 
gp: K.fu
 
Torsion generator:  \( -\frac{101}{179} a^{19} + \frac{3033}{2327} a^{18} - \frac{3686}{2327} a^{17} + \frac{2709}{2327} a^{16} - \frac{1459}{2327} a^{15} + \frac{4347}{2327} a^{14} + \frac{8679}{2327} a^{13} - \frac{753}{2327} a^{12} - \frac{3626}{2327} a^{11} + \frac{666}{2327} a^{10} + \frac{1692}{2327} a^{9} - \frac{32355}{2327} a^{8} - \frac{48901}{2327} a^{7} - \frac{39744}{2327} a^{6} - \frac{2475}{179} a^{5} - \frac{24462}{2327} a^{4} - \frac{11185}{2327} a^{3} + \frac{1774}{2327} a^{2} + \frac{732}{2327} a + \frac{44}{2327} \) (order $6$)
magma: K!f(TU.1) where TU,f is TorsionUnitGroup(K);
 
sage: UK.torsion_generator()
 
gp: K.tu[2]
 
Fundamental units:  Units are too long to display, but can be downloaded with other data for this field from 'Stored data to gp' link to the right
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 8452.6678373 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$D_4\times D_5$ (as 20T21):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 80
The 20 conjugacy class representatives for $D_4\times D_5$
Character table for $D_4\times D_5$

Intermediate fields

\(\Q(\sqrt{-3}) \), 4.0.117.1, 5.1.2209.1, 10.0.1185762483.1

Fields in the database are given up to isomorphism. Isomorphic intermediate fields are shown with their multiplicities.

Sibling fields

Degree 20 siblings: data not computed
Degree 40 siblings: data not computed

Frobenius cycle types

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59
Cycle type $20$ R ${\href{/LocalNumberField/5.4.0.1}{4} }^{5}$ ${\href{/LocalNumberField/7.10.0.1}{10} }{,}\,{\href{/LocalNumberField/7.5.0.1}{5} }^{2}$ ${\href{/LocalNumberField/11.4.0.1}{4} }^{5}$ R ${\href{/LocalNumberField/17.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/19.2.0.1}{2} }^{9}{,}\,{\href{/LocalNumberField/19.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/23.2.0.1}{2} }^{10}$ ${\href{/LocalNumberField/29.2.0.1}{2} }^{10}$ ${\href{/LocalNumberField/31.2.0.1}{2} }^{9}{,}\,{\href{/LocalNumberField/31.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/37.10.0.1}{10} }{,}\,{\href{/LocalNumberField/37.5.0.1}{5} }^{2}$ ${\href{/LocalNumberField/41.4.0.1}{4} }^{5}$ ${\href{/LocalNumberField/43.2.0.1}{2} }^{8}{,}\,{\href{/LocalNumberField/43.1.0.1}{1} }^{4}$ R ${\href{/LocalNumberField/53.10.0.1}{10} }^{2}$ $20$

In the table, R denotes a ramified prime. Cycle lengths which are repeated in a cycle type are indicated by exponents.

magma: p := 7; // to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$:
 
magma: idealfactors := Factorization(p*Integers(K)); // get the data
 
magma: [<primefactor[2], Valuation(Norm(primefactor[1]), p)> : primefactor in idealfactors];
 
sage: p = 7; # to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$:
 
sage: [(e, pr.norm().valuation(p)) for pr,e in K.factor(p)]
 
gp: p = 7; \\ to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$:
 
gp: idealfactors = idealprimedec(K, p); \\ get the data
 
gp: vector(length(idealfactors), j, [idealfactors[j][3], idealfactors[j][4]])
 

Local algebras for ramified primes

$p$LabelPolynomial $e$ $f$ $c$ Galois group Slope content
3Data not computed
$13$13.2.0.1$x^{2} - x + 2$$1$$2$$0$$C_2$$[\ ]^{2}$
13.2.0.1$x^{2} - x + 2$$1$$2$$0$$C_2$$[\ ]^{2}$
13.2.1.2$x^{2} + 26$$2$$1$$1$$C_2$$[\ ]_{2}$
13.2.0.1$x^{2} - x + 2$$1$$2$$0$$C_2$$[\ ]^{2}$
13.2.0.1$x^{2} - x + 2$$1$$2$$0$$C_2$$[\ ]^{2}$
13.2.0.1$x^{2} - x + 2$$1$$2$$0$$C_2$$[\ ]^{2}$
13.4.2.1$x^{4} + 39 x^{2} + 676$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
13.4.2.1$x^{4} + 39 x^{2} + 676$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
$47$47.4.0.1$x^{4} - x + 39$$1$$4$$0$$C_4$$[\ ]^{4}$
47.8.4.1$x^{8} + 172302 x^{4} - 103823 x^{2} + 7421994801$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$
47.8.4.1$x^{8} + 172302 x^{4} - 103823 x^{2} + 7421994801$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$