Properties

Label 20.20.2820251646...5077.1
Degree $20$
Signature $[20, 0]$
Discriminant $13^{9}\cdot 277^{10}$
Root discriminant $52.79$
Ramified primes $13, 277$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group $D_{20}$ (as 20T10)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![7, -113, 440, 1108, -8208, 787, 41379, -32272, -65218, 71526, 34045, -56895, -262, 18115, -2936, -2576, 590, 167, -42, -4, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^20 - 4*x^19 - 42*x^18 + 167*x^17 + 590*x^16 - 2576*x^15 - 2936*x^14 + 18115*x^13 - 262*x^12 - 56895*x^11 + 34045*x^10 + 71526*x^9 - 65218*x^8 - 32272*x^7 + 41379*x^6 + 787*x^5 - 8208*x^4 + 1108*x^3 + 440*x^2 - 113*x + 7)
 
gp: K = bnfinit(x^20 - 4*x^19 - 42*x^18 + 167*x^17 + 590*x^16 - 2576*x^15 - 2936*x^14 + 18115*x^13 - 262*x^12 - 56895*x^11 + 34045*x^10 + 71526*x^9 - 65218*x^8 - 32272*x^7 + 41379*x^6 + 787*x^5 - 8208*x^4 + 1108*x^3 + 440*x^2 - 113*x + 7, 1)
 

Normalized defining polynomial

\( x^{20} - 4 x^{19} - 42 x^{18} + 167 x^{17} + 590 x^{16} - 2576 x^{15} - 2936 x^{14} + 18115 x^{13} - 262 x^{12} - 56895 x^{11} + 34045 x^{10} + 71526 x^{9} - 65218 x^{8} - 32272 x^{7} + 41379 x^{6} + 787 x^{5} - 8208 x^{4} + 1108 x^{3} + 440 x^{2} - 113 x + 7 \)

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

Invariants

Degree:  $20$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[20, 0]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(28202516462559027773277004254095077=13^{9}\cdot 277^{10}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $52.79$
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:  $13, 277$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $a^{16}$, $a^{17}$, $a^{18}$, $\frac{1}{711633837560240033557229797} a^{19} - \frac{18198800965976411322392055}{101661976794320004793889971} a^{18} + \frac{49444385485559875485904685}{101661976794320004793889971} a^{17} + \frac{118166978235143203214502359}{711633837560240033557229797} a^{16} + \frac{98023082049470549481349439}{711633837560240033557229797} a^{15} - \frac{33421748439306953804759598}{711633837560240033557229797} a^{14} - \frac{4108501013393835821670689}{101661976794320004793889971} a^{13} + \frac{329295163045660417515011269}{711633837560240033557229797} a^{12} - \frac{1842520865924077705335381}{5350630357595789725994209} a^{11} - \frac{104189880726457995383515796}{711633837560240033557229797} a^{10} - \frac{239974265747986897454077610}{711633837560240033557229797} a^{9} - \frac{144704187928471633584852572}{711633837560240033557229797} a^{8} - \frac{278825841120892415857632584}{711633837560240033557229797} a^{7} + \frac{284766897787499205986793063}{711633837560240033557229797} a^{6} + \frac{21773768469630632882849752}{101661976794320004793889971} a^{5} + \frac{258926529168915423272425524}{711633837560240033557229797} a^{4} + \frac{32186183205007751677470196}{711633837560240033557229797} a^{3} - \frac{172006299422474213376389760}{711633837560240033557229797} a^{2} - \frac{349772068987914051780195130}{711633837560240033557229797} a - \frac{38941377815249785107124856}{101661976794320004793889971}$

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

Class group and class number

Trivial group, which has order $1$ (assuming GRH)

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

Unit group

magma: UK, f := UnitGroup(K);
 
sage: UK = K.unit_group()
 
Rank:  $19$
magma: UnitRank(K);
 
sage: UK.rank()
 
gp: K.fu
 
Torsion generator:  \( -1 \) (order $2$)
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 (assuming GRH)
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 84757731927.8 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$D_{20}$ (as 20T10):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 40
The 13 conjugacy class representatives for $D_{20}$
Character table for $D_{20}$

Intermediate fields

\(\Q(\sqrt{277}) \), 4.4.997477.1, 5.5.12967201.1, 10.10.46577079591509077.1

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

Sibling fields

Galois closure: data not computed
Degree 20 sibling: 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 $20$ ${\href{/LocalNumberField/3.5.0.1}{5} }^{4}$ $20$ ${\href{/LocalNumberField/7.2.0.1}{2} }^{9}{,}\,{\href{/LocalNumberField/7.1.0.1}{1} }^{2}$ $20$ R ${\href{/LocalNumberField/17.2.0.1}{2} }^{10}$ ${\href{/LocalNumberField/19.2.0.1}{2} }^{9}{,}\,{\href{/LocalNumberField/19.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/23.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/29.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/31.4.0.1}{4} }^{5}$ $20$ ${\href{/LocalNumberField/41.2.0.1}{2} }^{9}{,}\,{\href{/LocalNumberField/41.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/43.2.0.1}{2} }^{10}$ ${\href{/LocalNumberField/47.2.0.1}{2} }^{9}{,}\,{\href{/LocalNumberField/47.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/53.2.0.1}{2} }^{10}$ ${\href{/LocalNumberField/59.2.0.1}{2} }^{9}{,}\,{\href{/LocalNumberField/59.1.0.1}{1} }^{2}$

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
$13$13.2.0.1$x^{2} - x + 2$$1$$2$$0$$C_2$$[\ ]^{2}$
13.2.1.2$x^{2} + 26$$2$$1$$1$$C_2$$[\ ]_{2}$
13.4.2.1$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}$
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}$
277Data not computed