↑

Properties

Label 21.5.855...849.1
Degree $21$
Signature $[5, 8]$
Discriminant $8.559\times 10^{25}$
Root discriminant $17.17$
Ramified primes $23, 239, 431$
Class number $1$ (GRH)
Class group trivial (GRH)
Galois group 21T74

Related objects

Downloads

Learn more about

Show commands for: SageMath / Pari/GP / Magma

Normalized defining polynomial

sage: x = polygen(QQ); K.<a> = NumberField(x^21 - 4*x^19 + 23*x^17 - 4*x^16 - 54*x^15 + 19*x^14 + 94*x^13 - 41*x^12 - 115*x^11 + 59*x^10 + 30*x^9 - 81*x^8 + 20*x^7 + 46*x^6 - 18*x^5 - 5*x^4 + 13*x^3 - 3*x^2 + 1)
 
gp: K = bnfinit(x^21 - 4*x^19 + 23*x^17 - 4*x^16 - 54*x^15 + 19*x^14 + 94*x^13 - 41*x^12 - 115*x^11 + 59*x^10 + 30*x^9 - 81*x^8 + 20*x^7 + 46*x^6 - 18*x^5 - 5*x^4 + 13*x^3 - 3*x^2 + 1, 1)
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, 0, -3, 13, -5, -18, 46, 20, -81, 30, 59, -115, -41, 94, 19, -54, -4, 23, 0, -4, 0, 1]);
 

\( x^{21} - 4 x^{19} + 23 x^{17} - 4 x^{16} - 54 x^{15} + 19 x^{14} + 94 x^{13} - 41 x^{12} - 115 x^{11} + 59 x^{10} + 30 x^{9} - 81 x^{8} + 20 x^{7} + 46 x^{6} - 18 x^{5} - 5 x^{4} + 13 x^{3} - 3 x^{2} + 1 \)

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

Invariants

Degree:  $21$
sage: K.degree()
 
gp: poldegree(K.pol)
 
magma: Degree(K);
 
Signature:  $[5, 8]$
sage: K.signature()
 
gp: K.sign
 
magma: Signature(K);
 
Discriminant:  \(85594961606810871789418849\)\(\medspace = 23^{8}\cdot 239^{3}\cdot 431^{3}\)
sage: K.disc()
 
gp: K.disc
 
magma: Discriminant(Integers(K));
 
Root discriminant:  $17.17$
sage: (K.disc().abs())^(1./K.degree())
 
gp: abs(K.disc)^(1/poldegree(K.pol))
 
magma: Abs(Discriminant(Integers(K)))^(1/Degree(K));
 
Ramified primes:  $23, 239, 431$
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
magma: PrimeDivisors(Discriminant(Integers(K)));
 
$|\Aut(K/\Q)|$:  $1$
This field is not Galois over $\Q$.
This is not a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $a^{16}$, $a^{17}$, $a^{18}$, $\frac{1}{23} a^{19} + \frac{5}{23} a^{18} + \frac{9}{23} a^{17} + \frac{8}{23} a^{16} + \frac{1}{23} a^{15} - \frac{3}{23} a^{14} + \frac{11}{23} a^{13} - \frac{5}{23} a^{12} + \frac{6}{23} a^{11} + \frac{3}{23} a^{10} - \frac{11}{23} a^{9} - \frac{9}{23} a^{8} + \frac{2}{23} a^{7} - \frac{9}{23} a^{6} - \frac{3}{23} a^{5} + \frac{1}{23} a^{4} + \frac{6}{23} a^{2} - \frac{3}{23} a + \frac{2}{23}$, $\frac{1}{15425245952799023} a^{20} + \frac{129923724112386}{15425245952799023} a^{19} + \frac{188530018391087}{670662867513001} a^{18} + \frac{4524855785196851}{15425245952799023} a^{17} + \frac{5931120195708508}{15425245952799023} a^{16} + \frac{7697919585465984}{15425245952799023} a^{15} - \frac{3136030617859223}{15425245952799023} a^{14} + \frac{4242037863620116}{15425245952799023} a^{13} + \frac{36285041965030}{1402295086618093} a^{12} - \frac{2600135152275911}{15425245952799023} a^{11} + \frac{1769249277182147}{15425245952799023} a^{10} + \frac{1304321982046495}{15425245952799023} a^{9} + \frac{5275681306209044}{15425245952799023} a^{8} - \frac{3285219503385893}{15425245952799023} a^{7} - \frac{505211536564710}{1402295086618093} a^{6} + \frac{6757725086189783}{15425245952799023} a^{5} - \frac{1064082058819390}{15425245952799023} a^{4} - \frac{7503842779891147}{15425245952799023} a^{3} - \frac{29058979650835}{670662867513001} a^{2} + \frac{101136254658787}{15425245952799023} a + \frac{3181102975089609}{15425245952799023}$

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

Class group and class number

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

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

Unit group

sage: UK = K.unit_group()
 
magma: UK, f := UnitGroup(K);
 
Rank:  $12$
sage: UK.rank()
 
gp: K.fu
 
magma: UnitRank(K);
 
Torsion generator:  \( -1 \) (order $2$)
sage: UK.torsion_generator()
 
gp: K.tu[2]
 
magma: K!f(TU.1) where TU,f is TorsionUnitGroup(K);
 
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)
sage: UK.fundamental_units()
 
gp: K.fu
 
magma: [K!f(g): g in Generators(UK)];
 
Regulator:  \( 45009.9851463 \) (assuming GRH)
sage: K.regulator()
 
gp: K.reg
 
magma: Regulator(K);
 

Class number formula

$\displaystyle\lim_{s\to 1} (s-1)\zeta_K(s) \approx\frac{2^{5}\cdot(2\pi)^{8}\cdot 45009.9851463 \cdot 1}{2\sqrt{85594961606810871789418849}}\approx 0.189079174872$ (assuming GRH)

Galois group

21T74:

sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
magma: GaloisGroup(K);
 
A non-solvable group of order 30240
The 45 conjugacy class representatives for t21n74
Character table for t21n74 is not computed

Intermediate fields

3.1.23.1, 7.5.2369207.1

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

Sibling fields

Degree 42 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 $21$ $21$ ${\href{/LocalNumberField/5.10.0.1}{10} }{,}\,{\href{/LocalNumberField/5.5.0.1}{5} }{,}\,{\href{/LocalNumberField/5.2.0.1}{2} }^{3}$ ${\href{/LocalNumberField/7.6.0.1}{6} }{,}\,{\href{/LocalNumberField/7.4.0.1}{4} }^{3}{,}\,{\href{/LocalNumberField/7.3.0.1}{3} }$ ${\href{/LocalNumberField/11.10.0.1}{10} }{,}\,{\href{/LocalNumberField/11.5.0.1}{5} }{,}\,{\href{/LocalNumberField/11.2.0.1}{2} }^{3}$ $21$ ${\href{/LocalNumberField/17.14.0.1}{14} }{,}\,{\href{/LocalNumberField/17.7.0.1}{7} }$ ${\href{/LocalNumberField/19.4.0.1}{4} }^{3}{,}\,{\href{/LocalNumberField/19.2.0.1}{2} }^{4}{,}\,{\href{/LocalNumberField/19.1.0.1}{1} }$ R $15{,}\,{\href{/LocalNumberField/29.3.0.1}{3} }^{2}$ ${\href{/LocalNumberField/31.12.0.1}{12} }{,}\,{\href{/LocalNumberField/31.3.0.1}{3} }^{3}$ ${\href{/LocalNumberField/37.2.0.1}{2} }^{10}{,}\,{\href{/LocalNumberField/37.1.0.1}{1} }$ $15{,}\,{\href{/LocalNumberField/41.6.0.1}{6} }$ ${\href{/LocalNumberField/43.6.0.1}{6} }^{3}{,}\,{\href{/LocalNumberField/43.2.0.1}{2} }{,}\,{\href{/LocalNumberField/43.1.0.1}{1} }$ $15{,}\,{\href{/LocalNumberField/47.3.0.1}{3} }^{2}$ ${\href{/LocalNumberField/53.6.0.1}{6} }{,}\,{\href{/LocalNumberField/53.3.0.1}{3} }{,}\,{\href{/LocalNumberField/53.2.0.1}{2} }^{4}{,}\,{\href{/LocalNumberField/53.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/59.4.0.1}{4} }^{3}{,}\,{\href{/LocalNumberField/59.3.0.1}{3} }^{3}$

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

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]])
 
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];
 

Local algebras for ramified primes

$p$LabelPolynomial $e$ $f$ $c$ Galois group Slope content
$23$23.2.1.2$x^{2} + 46$$2$$1$$1$$C_2$$[\ ]_{2}$
23.2.1.2$x^{2} + 46$$2$$1$$1$$C_2$$[\ ]_{2}$
23.2.0.1$x^{2} - x + 7$$1$$2$$0$$C_2$$[\ ]^{2}$
23.2.1.2$x^{2} + 46$$2$$1$$1$$C_2$$[\ ]_{2}$
23.3.0.1$x^{3} - x + 4$$1$$3$$0$$C_3$$[\ ]^{3}$
23.4.2.1$x^{4} + 299 x^{2} + 25921$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
23.6.3.2$x^{6} - 529 x^{2} + 48668$$2$$3$$3$$C_6$$[\ ]_{2}^{3}$
239Data not computed
431Data not computed