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Properties

Label 20.0.25780541194...0000.1
Degree $20$
Signature $[0, 10]$
Discriminant $2^{50}\cdot 5^{20}\cdot 7^{4}$
Root discriminant $41.74$
Ramified primes $2, 5, 7$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group 20T872

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, 0, 130, 0, 965, 0, 1750, 0, 900, 0, 2, 0, 5, 0, 40, 0, 0, 0, 0, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^20 + 40*x^14 + 5*x^12 + 2*x^10 + 900*x^8 + 1750*x^6 + 965*x^4 + 130*x^2 + 1)
 
gp: K = bnfinit(x^20 + 40*x^14 + 5*x^12 + 2*x^10 + 900*x^8 + 1750*x^6 + 965*x^4 + 130*x^2 + 1, 1)
 

Normalized defining polynomial

\( x^{20} + 40 x^{14} + 5 x^{12} + 2 x^{10} + 900 x^{8} + 1750 x^{6} + 965 x^{4} + 130 x^{2} + 1 \)

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:  \(257805411942400000000000000000000=2^{50}\cdot 5^{20}\cdot 7^{4}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $41.74$
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:  $2, 5, 7$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $\frac{1}{5} a^{10} + \frac{1}{5}$, $\frac{1}{5} a^{11} + \frac{1}{5} a$, $\frac{1}{5} a^{12} + \frac{1}{5} a^{2}$, $\frac{1}{5} a^{13} + \frac{1}{5} a^{3}$, $\frac{1}{5} a^{14} + \frac{1}{5} a^{4}$, $\frac{1}{5} a^{15} + \frac{1}{5} a^{5}$, $\frac{1}{35} a^{16} - \frac{3}{35} a^{14} - \frac{3}{35} a^{12} + \frac{1}{35} a^{10} + \frac{2}{7} a^{8} + \frac{16}{35} a^{6} - \frac{3}{35} a^{4} - \frac{8}{35} a^{2} - \frac{4}{35}$, $\frac{1}{35} a^{17} - \frac{3}{35} a^{15} - \frac{3}{35} a^{13} + \frac{1}{35} a^{11} + \frac{2}{7} a^{9} + \frac{16}{35} a^{7} - \frac{3}{35} a^{5} - \frac{8}{35} a^{3} - \frac{4}{35} a$, $\frac{1}{196143745} a^{18} - \frac{1838982}{196143745} a^{16} + \frac{5990211}{196143745} a^{14} - \frac{2108787}{28020535} a^{12} - \frac{16069696}{196143745} a^{10} - \frac{54005774}{196143745} a^{8} + \frac{7759494}{28020535} a^{6} + \frac{3756331}{196143745} a^{4} + \frac{15754296}{196143745} a^{2} - \frac{45811506}{196143745}$, $\frac{1}{196143745} a^{19} - \frac{1838982}{196143745} a^{17} + \frac{5990211}{196143745} a^{15} - \frac{2108787}{28020535} a^{13} - \frac{16069696}{196143745} a^{11} - \frac{54005774}{196143745} a^{9} + \frac{7759494}{28020535} a^{7} + \frac{3756331}{196143745} a^{5} + \frac{15754296}{196143745} a^{3} - \frac{45811506}{196143745} a$

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:  $9$
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:  \( 214705246.545 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

20T872:

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 204800
The 116 conjugacy class representatives for t20n872 are not computed
Character table for t20n872 is not computed

Intermediate fields

\(\Q(\sqrt{2}) \), 10.6.15680000000000.1

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 R ${\href{/LocalNumberField/3.10.0.1}{10} }^{2}$ R R ${\href{/LocalNumberField/11.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/13.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/17.4.0.1}{4} }^{4}{,}\,{\href{/LocalNumberField/17.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/19.4.0.1}{4} }^{4}{,}\,{\href{/LocalNumberField/19.2.0.1}{2} }^{2}$ ${\href{/LocalNumberField/23.8.0.1}{8} }{,}\,{\href{/LocalNumberField/23.4.0.1}{4} }^{2}{,}\,{\href{/LocalNumberField/23.2.0.1}{2} }{,}\,{\href{/LocalNumberField/23.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/29.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/31.10.0.1}{10} }{,}\,{\href{/LocalNumberField/31.2.0.1}{2} }^{5}$ ${\href{/LocalNumberField/37.8.0.1}{8} }{,}\,{\href{/LocalNumberField/37.4.0.1}{4} }^{3}$ ${\href{/LocalNumberField/41.5.0.1}{5} }^{2}{,}\,{\href{/LocalNumberField/41.2.0.1}{2} }^{4}{,}\,{\href{/LocalNumberField/41.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/43.4.0.1}{4} }^{4}{,}\,{\href{/LocalNumberField/43.2.0.1}{2} }^{2}$ ${\href{/LocalNumberField/47.8.0.1}{8} }^{2}{,}\,{\href{/LocalNumberField/47.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/53.8.0.1}{8} }{,}\,{\href{/LocalNumberField/53.4.0.1}{4} }^{3}$ ${\href{/LocalNumberField/59.8.0.1}{8} }{,}\,{\href{/LocalNumberField/59.4.0.1}{4} }^{3}$

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
2Data not computed
$5$5.10.10.9$x^{10} + 10 x^{8} + 10 x^{6} + 10 x^{5} - 20 x^{4} - 20 x^{2} + 17$$5$$2$$10$$F_{5}\times C_2$$[5/4]_{4}^{2}$
5.10.10.9$x^{10} + 10 x^{8} + 10 x^{6} + 10 x^{5} - 20 x^{4} - 20 x^{2} + 17$$5$$2$$10$$F_{5}\times C_2$$[5/4]_{4}^{2}$
$7$$\Q_{7}$$x + 2$$1$$1$$0$Trivial$[\ ]$
$\Q_{7}$$x + 2$$1$$1$$0$Trivial$[\ ]$
7.2.0.1$x^{2} - x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
7.8.0.1$x^{8} - x + 3$$1$$8$$0$$C_8$$[\ ]^{8}$
7.8.4.1$x^{8} + 14 x^{6} + 539 x^{4} + 343 x^{2} + 60025$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$