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Properties

Label 8.0.11698585600.2
Degree $8$
Signature $[0, 4]$
Discriminant $2^{14}\cdot 5^{2}\cdot 13^{4}$
Root discriminant $18.13$
Ramified primes $2, 5, 13$
Class number $2$
Class group $[2]$
Galois group $((C_2 \times D_4): C_2):C_3$ (as 8T32)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![25, 0, 0, 0, 18, 0, -8, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^8 - 8*x^6 + 18*x^4 + 25)
 
gp: K = bnfinit(x^8 - 8*x^6 + 18*x^4 + 25, 1)
 

Normalized defining polynomial

\( x^{8} - 8 x^{6} + 18 x^{4} + 25 \)

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:  \(11698585600=2^{14}\cdot 5^{2}\cdot 13^{4}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $18.13$
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:  $2, 5, 13$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $\frac{1}{4} a^{4} - \frac{1}{2} a^{3} - \frac{1}{2} a^{2} - \frac{1}{2} a - \frac{1}{4}$, $\frac{1}{4} a^{5} - \frac{1}{2} a^{3} - \frac{1}{2} a^{2} - \frac{1}{4} a - \frac{1}{2}$, $\frac{1}{20} a^{6} + \frac{1}{10} a^{4} - \frac{1}{2} a^{3} + \frac{3}{20} a^{2} - \frac{1}{2} a$, $\frac{1}{40} a^{7} - \frac{1}{40} a^{6} - \frac{3}{40} a^{5} + \frac{3}{40} a^{4} - \frac{7}{40} a^{3} - \frac{13}{40} a^{2} + \frac{1}{8} a + \frac{3}{8}$

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:  \( \frac{1}{20} a^{7} - \frac{2}{5} a^{5} + \frac{23}{20} a^{3} - \frac{1}{2} a^{2} - \frac{1}{2} a + \frac{3}{2} \),  \( \frac{1}{8} a^{7} - \frac{1}{40} a^{6} - \frac{9}{8} a^{5} + \frac{13}{40} a^{4} + \frac{25}{8} a^{3} - \frac{53}{40} a^{2} - \frac{9}{8} a + \frac{13}{8} \),  \( \frac{3}{40} a^{7} + \frac{1}{8} a^{6} + \frac{1}{40} a^{5} + \frac{1}{8} a^{4} - \frac{41}{40} a^{3} - \frac{7}{8} a^{2} + \frac{17}{8} a - \frac{23}{8} \)
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 100.974661125 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_2^3:A_4$ (as 8T32):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 96
The 11 conjugacy class representatives for $((C_2 \times D_4): C_2):C_3$
Character table for $((C_2 \times D_4): C_2):C_3$

Intermediate fields

4.0.10816.1

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

Sibling fields

Degree 8 siblings: 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 ${\href{/LocalNumberField/3.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/3.1.0.1}{1} }^{2}$ R ${\href{/LocalNumberField/7.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/7.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/11.6.0.1}{6} }{,}\,{\href{/LocalNumberField/11.2.0.1}{2} }$ R ${\href{/LocalNumberField/17.6.0.1}{6} }{,}\,{\href{/LocalNumberField/17.2.0.1}{2} }$ ${\href{/LocalNumberField/19.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/19.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/23.6.0.1}{6} }{,}\,{\href{/LocalNumberField/23.2.0.1}{2} }$ ${\href{/LocalNumberField/29.6.0.1}{6} }{,}\,{\href{/LocalNumberField/29.2.0.1}{2} }$ ${\href{/LocalNumberField/31.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/37.6.0.1}{6} }{,}\,{\href{/LocalNumberField/37.2.0.1}{2} }$ ${\href{/LocalNumberField/41.6.0.1}{6} }{,}\,{\href{/LocalNumberField/41.2.0.1}{2} }$ ${\href{/LocalNumberField/43.6.0.1}{6} }{,}\,{\href{/LocalNumberField/43.2.0.1}{2} }$ ${\href{/LocalNumberField/47.2.0.1}{2} }^{2}{,}\,{\href{/LocalNumberField/47.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/53.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/59.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/59.1.0.1}{1} }^{2}$

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$2.8.14.2$x^{8} + 2 x^{7} + 2$$8$$1$$14$$A_4\times C_2$$[2, 2, 2]^{3}$
$5$5.4.2.2$x^{4} - 5 x^{2} + 50$$2$$2$$2$$C_4$$[\ ]_{2}^{2}$
5.4.0.1$x^{4} + x^{2} - 2 x + 2$$1$$4$$0$$C_4$$[\ ]^{4}$
$13$$\Q_{13}$$x + 2$$1$$1$$0$Trivial$[\ ]$
$\Q_{13}$$x + 2$$1$$1$$0$Trivial$[\ ]$
13.3.2.2$x^{3} - 13$$3$$1$$2$$C_3$$[\ ]_{3}$
13.3.2.2$x^{3} - 13$$3$$1$$2$$C_3$$[\ ]_{3}$

Artin representations

Label Dimension Conductor Defining polynomial of Artin field $G$ Ind $\chi(c)$
* 1.1.1t1.1c1$1$ $1$ $x$ $C_1$ $1$ $1$
1.13.3t1.1c1$1$ $ 13 $ $x^{3} - x^{2} - 4 x - 1$ $C_3$ (as 3T1) $0$ $1$
1.13.3t1.1c2$1$ $ 13 $ $x^{3} - x^{2} - 4 x - 1$ $C_3$ (as 3T1) $0$ $1$
3.2e6_5e2_13e2.4t4.2c1$3$ $ 2^{6} \cdot 5^{2} \cdot 13^{2}$ $x^{4} - 2 x^{3} - 10 x^{2} + 6 x + 19$ $A_4$ (as 4T4) $1$ $3$
3.2e6_5e2_13e2.4t4.1c1$3$ $ 2^{6} \cdot 5^{2} \cdot 13^{2}$ $x^{4} - 2 x^{3} + 6 x^{2} + 10$ $A_4$ (as 4T4) $1$ $-1$
3.5e2_13e2.4t4.1c1$3$ $ 5^{2} \cdot 13^{2}$ $x^{4} - x^{3} - 3 x + 4$ $A_4$ (as 4T4) $1$ $-1$
3.2e6_5e2_13e2.4t4.3c1$3$ $ 2^{6} \cdot 5^{2} \cdot 13^{2}$ $x^{4} - 2 x^{3} + 2 x^{2} + 4 x + 54$ $A_4$ (as 4T4) $1$ $-1$
* 3.2e6_13e2.4t4.1c1$3$ $ 2^{6} \cdot 13^{2}$ $x^{4} - 2 x^{3} + 2 x^{2} + 4 x + 2$ $A_4$ (as 4T4) $1$ $-1$
* 4.2e8_5e2_13e2.8t32.6c1$4$ $ 2^{8} \cdot 5^{2} \cdot 13^{2}$ $x^{8} - 8 x^{6} + 18 x^{4} + 25$ $((C_2 \times D_4): C_2):C_3$ (as 8T32) $1$ $0$
4.2e8_5e2_13e3.24t97.6c1$4$ $ 2^{8} \cdot 5^{2} \cdot 13^{3}$ $x^{8} - 8 x^{6} + 18 x^{4} + 25$ $((C_2 \times D_4): C_2):C_3$ (as 8T32) $0$ $0$
4.2e8_5e2_13e3.24t97.6c2$4$ $ 2^{8} \cdot 5^{2} \cdot 13^{3}$ $x^{8} - 8 x^{6} + 18 x^{4} + 25$ $((C_2 \times D_4): C_2):C_3$ (as 8T32) $0$ $0$

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 *.