Properties

Label 20.10.4936006137...1875.1
Degree $20$
Signature $[10, 5]$
Discriminant $-\,5^{10}\cdot 11^{17}$
Root discriminant $17.17$
Ramified primes $5, 11$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group $C_5\times D_4$ (as 20T12)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![-1, -2, 24, 46, -110, -75, 270, -175, -158, 407, -318, -1, 233, -215, 65, 45, -60, 28, -1, -4, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^20 - 4*x^19 - x^18 + 28*x^17 - 60*x^16 + 45*x^15 + 65*x^14 - 215*x^13 + 233*x^12 - x^11 - 318*x^10 + 407*x^9 - 158*x^8 - 175*x^7 + 270*x^6 - 75*x^5 - 110*x^4 + 46*x^3 + 24*x^2 - 2*x - 1)
 
gp: K = bnfinit(x^20 - 4*x^19 - x^18 + 28*x^17 - 60*x^16 + 45*x^15 + 65*x^14 - 215*x^13 + 233*x^12 - x^11 - 318*x^10 + 407*x^9 - 158*x^8 - 175*x^7 + 270*x^6 - 75*x^5 - 110*x^4 + 46*x^3 + 24*x^2 - 2*x - 1, 1)
 

Normalized defining polynomial

\( x^{20} - 4 x^{19} - x^{18} + 28 x^{17} - 60 x^{16} + 45 x^{15} + 65 x^{14} - 215 x^{13} + 233 x^{12} - x^{11} - 318 x^{10} + 407 x^{9} - 158 x^{8} - 175 x^{7} + 270 x^{6} - 75 x^{5} - 110 x^{4} + 46 x^{3} + 24 x^{2} - 2 x - 1 \)

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

Invariants

Degree:  $20$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[10, 5]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(-4936006137688415732421875=-\,5^{10}\cdot 11^{17}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $17.17$
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:  $5, 11$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $a^{16}$, $a^{17}$, $a^{18}$, $\frac{1}{468238596550385959} a^{19} + \frac{31561617846187413}{468238596550385959} a^{18} + \frac{232319717662641602}{468238596550385959} a^{17} - \frac{64048574701025375}{468238596550385959} a^{16} + \frac{75851900668974160}{468238596550385959} a^{15} + \frac{54987615982025592}{468238596550385959} a^{14} + \frac{14361844544542553}{468238596550385959} a^{13} - \frac{105122907236779295}{468238596550385959} a^{12} - \frac{116973137940060106}{468238596550385959} a^{11} - \frac{201538677102207954}{468238596550385959} a^{10} - \frac{70249049007198466}{468238596550385959} a^{9} + \frac{64936547287265046}{468238596550385959} a^{8} - \frac{57757511490261294}{468238596550385959} a^{7} + \frac{221348321038386811}{468238596550385959} a^{6} + \frac{4166937864215002}{468238596550385959} a^{5} - \frac{56068451653526706}{468238596550385959} a^{4} + \frac{173531938015225787}{468238596550385959} a^{3} + \frac{121599202523473067}{468238596550385959} a^{2} + \frac{203102775176949614}{468238596550385959} a + \frac{91388427023054715}{468238596550385959}$

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:  $14$
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:  \( 63613.3081038 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_5\times D_4$ (as 20T12):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 40
The 25 conjugacy class representatives for $C_5\times D_4$
Character table for $C_5\times D_4$ is not computed

Intermediate fields

\(\Q(\sqrt{5}) \), 4.2.275.1, \(\Q(\zeta_{11})^+\), 10.10.669871503125.1

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 $20$ ${\href{/LocalNumberField/3.10.0.1}{10} }^{2}$ R $20$ R $20$ $20$ ${\href{/LocalNumberField/19.10.0.1}{10} }{,}\,{\href{/LocalNumberField/19.5.0.1}{5} }^{2}$ ${\href{/LocalNumberField/23.2.0.1}{2} }^{10}$ ${\href{/LocalNumberField/29.10.0.1}{10} }{,}\,{\href{/LocalNumberField/29.5.0.1}{5} }^{2}$ ${\href{/LocalNumberField/31.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/37.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/41.10.0.1}{10} }{,}\,{\href{/LocalNumberField/41.5.0.1}{5} }^{2}$ ${\href{/LocalNumberField/43.4.0.1}{4} }^{5}$ ${\href{/LocalNumberField/47.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/53.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/59.5.0.1}{5} }^{4}$

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
5Data not computed
$11$11.10.9.1$x^{10} - 11$$10$$1$$9$$C_{10}$$[\ ]_{10}$
11.10.8.5$x^{10} - 2321 x^{5} + 2033647$$5$$2$$8$$C_{10}$$[\ ]_{5}^{2}$