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Properties

Label 8.0.5861899530496.2
Degree $8$
Signature $[0, 4]$
Discriminant $2^{8}\cdot 389^{4}$
Root discriminant $39.45$
Ramified primes $2, 389$
Class number $2$
Class group $[2]$
Galois group $V_4^2:S_3$ (as 8T34)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![13, -42, 46, -8, 25, -4, 4, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^8 + 4*x^6 - 4*x^5 + 25*x^4 - 8*x^3 + 46*x^2 - 42*x + 13)
 
gp: K = bnfinit(x^8 + 4*x^6 - 4*x^5 + 25*x^4 - 8*x^3 + 46*x^2 - 42*x + 13, 1)
 

Normalized defining polynomial

\( x^{8} + 4 x^{6} - 4 x^{5} + 25 x^{4} - 8 x^{3} + 46 x^{2} - 42 x + 13 \)

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

Invariants

Degree:  $8$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[0, 4]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(5861899530496=2^{8}\cdot 389^{4}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $39.45$
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:  $2, 389$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $\frac{1}{3} a^{6} - \frac{1}{3} a^{5} + \frac{1}{3} a^{3} - \frac{1}{3} a - \frac{1}{3}$, $\frac{1}{411} a^{7} - \frac{4}{411} a^{6} - \frac{39}{137} a^{5} + \frac{190}{411} a^{4} + \frac{29}{137} a^{3} - \frac{82}{411} a^{2} - \frac{37}{411} a - \frac{56}{137}$

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

Class group and class number

$C_{2}$, which has order $2$

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

Unit group

magma: UK, f := UnitGroup(K);
 
sage: UK = K.unit_group()
 
Rank:  $3$
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:  \( \frac{151}{411} a^{7} + \frac{27}{137} a^{6} + \frac{554}{411} a^{5} - \frac{80}{411} a^{4} + \frac{3136}{411} a^{3} + \frac{1181}{411} a^{2} + \frac{6058}{411} a - \frac{2215}{411} \),  \( \frac{178}{411} a^{7} - \frac{164}{411} a^{6} + \frac{409}{411} a^{5} - \frac{704}{411} a^{4} + \frac{4115}{411} a^{3} - \frac{3499}{411} a^{2} + \frac{362}{137} a - \frac{38}{411} \),  \( 130 a^{4} + 260 a^{2} - 260 a + 2647 \)
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 1573.14877111 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_2^2:S_4$ (as 8T34):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 96
The 10 conjugacy class representatives for $V_4^2:S_3$
Character table for $V_4^2:S_3$

Intermediate fields

\(\Q(\sqrt{389}) \)

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

Sibling fields

Degree 12 siblings: data not computed
Degree 16 sibling: data not computed
Degree 24 siblings: data not computed
Degree 32 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 R ${\href{/LocalNumberField/3.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/5.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/5.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/7.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/7.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/11.2.0.1}{2} }^{2}{,}\,{\href{/LocalNumberField/11.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/13.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/13.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/17.2.0.1}{2} }^{2}{,}\,{\href{/LocalNumberField/17.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/19.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/19.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/23.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/29.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/31.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/37.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/41.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/41.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/43.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/47.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/53.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/59.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/59.1.0.1}{1} }^{2}$

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
$2$2.8.8.11$x^{8} + 20 x^{2} + 4$$4$$2$$8$$S_4$$[4/3, 4/3]_{3}^{2}$
389Data not computed

Artin representations

Label Dimension Conductor Defining polynomial of Artin field $G$ Ind $\chi(c)$
* 1.1.1t1.1c1$1$ $1$ $x$ $C_1$ $1$ $1$
* 1.389.2t1.1c1$1$ $ 389 $ $x^{2} - x - 97$ $C_2$ (as 2T1) $1$ $1$
2.2e2_389.3t2.1c1$2$ $ 2^{2} \cdot 389 $ $x^{3} - x^{2} - 9 x + 11$ $S_3$ (as 3T2) $1$ $2$
3.2e2_389e2.6t8.1c1$3$ $ 2^{2} \cdot 389^{2}$ $x^{4} - x^{3} - x^{2} + x + 2$ $S_4$ (as 4T5) $1$ $-1$
3.2e4_389.4t5.1c1$3$ $ 2^{4} \cdot 389 $ $x^{4} + 4 x^{2} - 2 x + 3$ $S_4$ (as 4T5) $1$ $-1$
3.2e4_389e2.6t8.2c1$3$ $ 2^{4} \cdot 389^{2}$ $x^{4} - 6 x^{2} - 2 x + 5$ $S_4$ (as 4T5) $1$ $3$
3.2e2_389.4t5.1c1$3$ $ 2^{2} \cdot 389 $ $x^{4} - x^{3} - x^{2} + x + 2$ $S_4$ (as 4T5) $1$ $-1$
3.2e4_389e2.6t8.1c1$3$ $ 2^{4} \cdot 389^{2}$ $x^{4} + 4 x^{2} - 2 x + 3$ $S_4$ (as 4T5) $1$ $-1$
3.2e4_389.4t5.2c1$3$ $ 2^{4} \cdot 389 $ $x^{4} - 6 x^{2} - 2 x + 5$ $S_4$ (as 4T5) $1$ $3$
* 6.2e8_389e3.8t34.1c1$6$ $ 2^{8} \cdot 389^{3}$ $x^{8} + 4 x^{6} - 4 x^{5} + 25 x^{4} - 8 x^{3} + 46 x^{2} - 42 x + 13$ $V_4^2:S_3$ (as 8T34) $1$ $-2$

Data is given for all irreducible representations of the Galois group for the Galois closure of this field. Those marked with * are summands in the permutation representation coming from this field. Representations which appear with multiplicity greater than one are indicated by exponents on the *.