Properties

Label 8.0.1146228736.5
Degree $8$
Signature $[0, 4]$
Discriminant $2^{12}\cdot 23^{4}$
Root discriminant $13.56$
Ramified primes $2, 23$
Class number $3$
Class group $[3]$
Galois Group $D_4$ (as 8T4)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![36, 24, 86, 104, 43, -4, -6, 0, 1]);
sage: x = polygen(QQ); K.<a> = NumberField(x^8 - 6*x^6 - 4*x^5 + 43*x^4 + 104*x^3 + 86*x^2 + 24*x + 36)
gp: K = bnfinit(x^8 - 6*x^6 - 4*x^5 + 43*x^4 + 104*x^3 + 86*x^2 + 24*x + 36, 1)

Normalized defining polynomial

\(x^{8} \) \(\mathstrut -\mathstrut 6 x^{6} \) \(\mathstrut -\mathstrut 4 x^{5} \) \(\mathstrut +\mathstrut 43 x^{4} \) \(\mathstrut +\mathstrut 104 x^{3} \) \(\mathstrut +\mathstrut 86 x^{2} \) \(\mathstrut +\mathstrut 24 x \) \(\mathstrut +\mathstrut 36 \)

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:  \(1146228736=2^{12}\cdot 23^{4}\)
magma: Discriminant(K);
sage: K.disc()
gp: K.disc
Root discriminant:  $13.56$
magma: Abs(Discriminant(K))^(1/Degree(K));
sage: (K.disc().abs())^(1./K.degree())
gp: abs(K.disc)^(1/poldegree(K.pol))
Ramified primes:  $2, 23$
magma: PrimeDivisors(Discriminant(K));
sage: K.disc().support()
gp: factor(abs(K.disc))[,1]~
This field is Galois over $\Q$.
This is not a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $\frac{1}{2} a^{4} - \frac{1}{2} a^{2}$, $\frac{1}{2} a^{5} - \frac{1}{2} a^{3}$, $\frac{1}{30} a^{6} + \frac{1}{6} a^{5} + \frac{7}{30} a^{4} + \frac{1}{30} a^{3} - \frac{1}{5} a^{2} + \frac{1}{15} a - \frac{2}{5}$, $\frac{1}{24270} a^{7} + \frac{51}{4045} a^{6} - \frac{341}{8090} a^{5} + \frac{1234}{12135} a^{4} - \frac{440}{2427} a^{3} + \frac{1558}{12135} a^{2} - \frac{751}{2427} a - \frac{1967}{4045}$

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

Class group and class number

Multiplicative Abelian group isomorphic to C3, order $3$

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:  \( \frac{92}{4045} a^{7} - \frac{169}{24270} a^{6} - \frac{2441}{24270} a^{5} - \frac{1628}{12135} a^{4} + \frac{23279}{24270} a^{3} + \frac{17561}{8090} a^{2} + \frac{27404}{12135} a + \frac{4748}{4045} \),  \( \frac{133}{12135} a^{7} - \frac{313}{24270} a^{6} - \frac{1103}{24270} a^{5} - \frac{14}{809} a^{4} + \frac{9931}{24270} a^{3} + \frac{4133}{4854} a^{2} - \frac{524}{12135} a + \frac{201}{4045} \),  \( \frac{133}{12135} a^{7} - \frac{313}{24270} a^{6} - \frac{1103}{24270} a^{5} - \frac{14}{809} a^{4} + \frac{9931}{24270} a^{3} + \frac{4133}{4854} a^{2} - \frac{524}{12135} a - \frac{3844}{4045} \)
magma: [K!f(g): g in Generators(UK)];
sage: UK.fundamental_units()
gp: K.fu
Regulator:  \( 7.19956921879 \)
magma: Regulator(K);
sage: K.regulator()
gp: K.reg

Galois group

$D_4$ (as 8T4):

magma: GaloisGroup(K);
sage: K.galois_group(type='pari')
gp: polgalois(K.pol)
A solvable group of order 8
The 5 conjugacy class representatives for $D_4$
Character table for $D_4$

Intermediate fields

\(\Q(\sqrt{-46}) \), \(\Q(\sqrt{-23}) \), \(\Q(\sqrt{2}) \), \(\Q(\sqrt{2}, \sqrt{-23})\), 4.0.4232.1 x2, 4.2.1472.2 x2

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

Sibling fields

Degree 4 siblings: 4.2.1472.2, 4.0.4232.1

Frobenius cycle types

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59
Cycle type R ${\href{/LocalNumberField/3.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/5.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/7.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/11.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/13.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/17.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/19.4.0.1}{4} }^{2}$ R ${\href{/LocalNumberField/29.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/31.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/37.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/41.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/43.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/47.1.0.1}{1} }^{8}$ ${\href{/LocalNumberField/53.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/59.2.0.1}{2} }^{4}$

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
$2$2.4.6.1$x^{4} - 6 x^{2} + 4$$2$$2$$6$$V_4$$[3]^{2}$
2.4.6.1$x^{4} - 6 x^{2} + 4$$2$$2$$6$$V_4$$[3]^{2}$
$23$23.4.2.1$x^{4} + 299 x^{2} + 25921$$2$$2$$2$$V_4$$[\ ]_{2}^{2}$
23.4.2.1$x^{4} + 299 x^{2} + 25921$$2$$2$$2$$V_4$$[\ ]_{2}^{2}$

Artin representations

Label Dimension Conductor Defining polynomial of Artin field $G$ Ind $\chi(c)$
* 1.1.1t1.1c1$1$ $1$ $x$ $C_1$ $1$ $1$
* 1.2e3.2t1.1c1$1$ $ 2^{3}$ $x^{2} - 2$ $C_2$ (as 2T1) $1$ $1$
* 1.23.2t1.1c1$1$ $ 23 $ $x^{2} - x + 6$ $C_2$ (as 2T1) $1$ $-1$
* 1.2e3_23.2t1.2c1$1$ $ 2^{3} \cdot 23 $ $x^{2} + 46$ $C_2$ (as 2T1) $1$ $-1$
*2 2.2e3_23.4t3.3c1$2$ $ 2^{3} \cdot 23 $ $x^{8} - 6 x^{6} - 4 x^{5} + 43 x^{4} + 104 x^{3} + 86 x^{2} + 24 x + 36$ $D_4$ (as 8T4) $1$ $0$

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 *.