Properties

Label 8.0.378956381627633.1
Degree $8$
Signature $[0, 4]$
Discriminant $17^{7}\cdot 31^{4}$
Root discriminant $66.42$
Ramified primes $17, 31$
Class number $306$
Class group $[3, 102]$
Galois group $C_8$ (as 8T1)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![136001, -84180, 39566, -7082, 3823, -130, 129, -1, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^8 - x^7 + 129*x^6 - 130*x^5 + 3823*x^4 - 7082*x^3 + 39566*x^2 - 84180*x + 136001)
 
gp: K = bnfinit(x^8 - x^7 + 129*x^6 - 130*x^5 + 3823*x^4 - 7082*x^3 + 39566*x^2 - 84180*x + 136001, 1)
 

Normalized defining polynomial

\( x^{8} - x^{7} + 129 x^{6} - 130 x^{5} + 3823 x^{4} - 7082 x^{3} + 39566 x^{2} - 84180 x + 136001 \)

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:  \(378956381627633=17^{7}\cdot 31^{4}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $66.42$
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:  $17, 31$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(527=17\cdot 31\)
Dirichlet character group:    $\lbrace$$\chi_{527}(1,·)$, $\chi_{527}(497,·)$, $\chi_{527}(495,·)$, $\chi_{527}(433,·)$, $\chi_{527}(404,·)$, $\chi_{527}(373,·)$, $\chi_{527}(247,·)$, $\chi_{527}(185,·)$$\rbrace$
This is a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $\frac{1}{13} a^{6} - \frac{2}{13} a^{5} - \frac{5}{13} a^{4} + \frac{4}{13} a^{3} + \frac{1}{13} a^{2} + \frac{4}{13} a - \frac{3}{13}$, $\frac{1}{79218665073197} a^{7} + \frac{994098796316}{79218665073197} a^{6} + \frac{558040874133}{6093743467169} a^{5} + \frac{35957529759096}{79218665073197} a^{4} - \frac{15006542934639}{79218665073197} a^{3} - \frac{39312357447875}{79218665073197} a^{2} - \frac{1564589944643}{6093743467169} a - \frac{1529410003523}{79218665073197}$

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

Class group and class number

$C_{3}\times C_{102}$, which has order $306$

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:  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
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 27.6959098582 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_8$ (as 8T1):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A cyclic group of order 8
The 8 conjugacy class representatives for $C_8$
Character table for $C_8$

Intermediate fields

\(\Q(\sqrt{17}) \), 4.4.4913.1

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

Frobenius cycle types

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59
Cycle type ${\href{/LocalNumberField/2.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/3.8.0.1}{8} }$ ${\href{/LocalNumberField/5.8.0.1}{8} }$ ${\href{/LocalNumberField/7.8.0.1}{8} }$ ${\href{/LocalNumberField/11.8.0.1}{8} }$ ${\href{/LocalNumberField/13.1.0.1}{1} }^{8}$ R ${\href{/LocalNumberField/19.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/23.8.0.1}{8} }$ ${\href{/LocalNumberField/29.8.0.1}{8} }$ R ${\href{/LocalNumberField/37.8.0.1}{8} }$ ${\href{/LocalNumberField/41.8.0.1}{8} }$ ${\href{/LocalNumberField/43.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/47.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/53.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/59.4.0.1}{4} }^{2}$

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
$17$17.8.7.1$x^{8} - 1377$$8$$1$$7$$C_8$$[\ ]_{8}$
$31$31.8.4.2$x^{8} - 59582 x^{2} + 15699857$$2$$4$$4$$C_8$$[\ ]_{2}^{4}$

Artin representations

Label Dimension Conductor Defining polynomial of Artin field $G$ Ind $\chi(c)$
* 1.1.1t1.1c1$1$ $1$ $x$ $C_1$ $1$ $1$
* 1.17_31.8t1.1c1$1$ $ 17 \cdot 31 $ $x^{8} - x^{7} + 129 x^{6} - 130 x^{5} + 3823 x^{4} - 7082 x^{3} + 39566 x^{2} - 84180 x + 136001$ $C_8$ (as 8T1) $0$ $-1$
* 1.17.4t1.1c1$1$ $ 17 $ $x^{4} - x^{3} - 6 x^{2} + x + 1$ $C_4$ (as 4T1) $0$ $1$
* 1.17_31.8t1.1c2$1$ $ 17 \cdot 31 $ $x^{8} - x^{7} + 129 x^{6} - 130 x^{5} + 3823 x^{4} - 7082 x^{3} + 39566 x^{2} - 84180 x + 136001$ $C_8$ (as 8T1) $0$ $-1$
* 1.17.2t1.1c1$1$ $ 17 $ $x^{2} - x - 4$ $C_2$ (as 2T1) $1$ $1$
* 1.17_31.8t1.1c3$1$ $ 17 \cdot 31 $ $x^{8} - x^{7} + 129 x^{6} - 130 x^{5} + 3823 x^{4} - 7082 x^{3} + 39566 x^{2} - 84180 x + 136001$ $C_8$ (as 8T1) $0$ $-1$
* 1.17.4t1.1c2$1$ $ 17 $ $x^{4} - x^{3} - 6 x^{2} + x + 1$ $C_4$ (as 4T1) $0$ $1$
* 1.17_31.8t1.1c4$1$ $ 17 \cdot 31 $ $x^{8} - x^{7} + 129 x^{6} - 130 x^{5} + 3823 x^{4} - 7082 x^{3} + 39566 x^{2} - 84180 x + 136001$ $C_8$ (as 8T1) $0$ $-1$

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 *.