Properties

Label 20.8.50246550232...3761.1
Degree $20$
Signature $[8, 6]$
Discriminant $37^{4}\cdot 401^{9}$
Root discriminant $30.55$
Ramified primes $37, 401$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group $C_2\times C_2^4:D_5$ (as 20T87)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![9, 0, -8, 58, -144, -193, 338, 327, -589, -215, 855, -432, -128, 102, -49, 165, -138, 23, 17, -8, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^20 - 8*x^19 + 17*x^18 + 23*x^17 - 138*x^16 + 165*x^15 - 49*x^14 + 102*x^13 - 128*x^12 - 432*x^11 + 855*x^10 - 215*x^9 - 589*x^8 + 327*x^7 + 338*x^6 - 193*x^5 - 144*x^4 + 58*x^3 - 8*x^2 + 9)
 
gp: K = bnfinit(x^20 - 8*x^19 + 17*x^18 + 23*x^17 - 138*x^16 + 165*x^15 - 49*x^14 + 102*x^13 - 128*x^12 - 432*x^11 + 855*x^10 - 215*x^9 - 589*x^8 + 327*x^7 + 338*x^6 - 193*x^5 - 144*x^4 + 58*x^3 - 8*x^2 + 9, 1)
 

Normalized defining polynomial

\( x^{20} - 8 x^{19} + 17 x^{18} + 23 x^{17} - 138 x^{16} + 165 x^{15} - 49 x^{14} + 102 x^{13} - 128 x^{12} - 432 x^{11} + 855 x^{10} - 215 x^{9} - 589 x^{8} + 327 x^{7} + 338 x^{6} - 193 x^{5} - 144 x^{4} + 58 x^{3} - 8 x^{2} + 9 \)

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

Invariants

Degree:  $20$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[8, 6]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(502465502329909572653052213761=37^{4}\cdot 401^{9}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $30.55$
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:  $37, 401$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $a^{16}$, $a^{17}$, $\frac{1}{93} a^{18} + \frac{26}{93} a^{17} - \frac{11}{93} a^{16} + \frac{8}{31} a^{15} + \frac{5}{31} a^{14} - \frac{3}{31} a^{13} + \frac{8}{93} a^{12} + \frac{26}{93} a^{11} - \frac{10}{31} a^{10} + \frac{13}{31} a^{9} - \frac{11}{31} a^{8} + \frac{16}{93} a^{7} + \frac{4}{31} a^{6} - \frac{4}{93} a^{4} + \frac{43}{93} a^{3} + \frac{37}{93} a^{2} + \frac{44}{93} a + \frac{5}{31}$, $\frac{1}{2304565836894744487689} a^{19} - \frac{3369228529022442936}{768188612298248162563} a^{18} - \frac{92381023688525533212}{768188612298248162563} a^{17} - \frac{448846646361219404075}{2304565836894744487689} a^{16} - \frac{290363557822853520093}{768188612298248162563} a^{15} - \frac{225283851528110319541}{768188612298248162563} a^{14} - \frac{149804831995221427645}{2304565836894744487689} a^{13} + \frac{785002550761317624307}{2304565836894744487689} a^{12} + \frac{452247517494414620909}{2304565836894744487689} a^{11} + \frac{11884564015331880428}{24780277816072521373} a^{10} - \frac{79378041049040086923}{768188612298248162563} a^{9} + \frac{44855411675854904350}{2304565836894744487689} a^{8} + \frac{1006343401341947442331}{2304565836894744487689} a^{7} + \frac{369527539547723615512}{768188612298248162563} a^{6} - \frac{823137178685520868225}{2304565836894744487689} a^{5} + \frac{349608231448755304556}{768188612298248162563} a^{4} - \frac{631464616190697906613}{2304565836894744487689} a^{3} + \frac{120239563119105944749}{768188612298248162563} a^{2} + \frac{272152014558449002922}{2304565836894744487689} a + \frac{188650833148954235656}{768188612298248162563}$

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:  $13$
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:  \( 22330368.8867 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_2\times C_2^4:D_5$ (as 20T87):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 320
The 20 conjugacy class representatives for $C_2\times C_2^4:D_5$
Character table for $C_2\times C_2^4:D_5$

Intermediate fields

5.5.160801.1, 10.6.35398180431769.1

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

Sibling fields

Degree 10 siblings: data not computed
Degree 20 siblings: data not computed
Degree 32 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 ${\href{/LocalNumberField/2.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/3.4.0.1}{4} }^{3}{,}\,{\href{/LocalNumberField/3.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/5.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/7.5.0.1}{5} }^{4}$ ${\href{/LocalNumberField/11.5.0.1}{5} }^{4}$ ${\href{/LocalNumberField/13.4.0.1}{4} }^{5}$ ${\href{/LocalNumberField/17.4.0.1}{4} }^{5}$ ${\href{/LocalNumberField/19.4.0.1}{4} }^{3}{,}\,{\href{/LocalNumberField/19.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/23.4.0.1}{4} }^{3}{,}\,{\href{/LocalNumberField/23.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/29.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/31.4.0.1}{4} }^{3}{,}\,{\href{/LocalNumberField/31.2.0.1}{2} }^{4}$ R ${\href{/LocalNumberField/41.5.0.1}{5} }^{4}$ ${\href{/LocalNumberField/43.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/47.5.0.1}{5} }^{4}$ ${\href{/LocalNumberField/53.4.0.1}{4} }^{4}{,}\,{\href{/LocalNumberField/53.2.0.1}{2} }{,}\,{\href{/LocalNumberField/53.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/59.2.0.1}{2} }^{9}{,}\,{\href{/LocalNumberField/59.1.0.1}{1} }^{2}$

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
$37$37.4.2.1$x^{4} + 333 x^{2} + 34225$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
37.4.0.1$x^{4} - x + 2$$1$$4$$0$$C_4$$[\ ]^{4}$
37.4.0.1$x^{4} - x + 2$$1$$4$$0$$C_4$$[\ ]^{4}$
37.4.0.1$x^{4} - x + 2$$1$$4$$0$$C_4$$[\ ]^{4}$
37.4.2.1$x^{4} + 333 x^{2} + 34225$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
401Data not computed