Properties

Label 8.0.3490111457856.5
Degree $8$
Signature $[0, 4]$
Discriminant $2^{6}\cdot 3^{10}\cdot 31^{4}$
Root discriminant $36.97$
Ramified primes $2, 3, 31$
Class number $2$
Class group $[2]$
Galois group $C_2^3:(C_7: C_3)$ (as 8T36)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![54, -162, 198, -90, -18, 30, 6, -3, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^8 - 3*x^7 + 6*x^6 + 30*x^5 - 18*x^4 - 90*x^3 + 198*x^2 - 162*x + 54)
 
gp: K = bnfinit(x^8 - 3*x^7 + 6*x^6 + 30*x^5 - 18*x^4 - 90*x^3 + 198*x^2 - 162*x + 54, 1)
 

Normalized defining polynomial

\( x^{8} - 3 x^{7} + 6 x^{6} + 30 x^{5} - 18 x^{4} - 90 x^{3} + 198 x^{2} - 162 x + 54 \)

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:  \(3490111457856=2^{6}\cdot 3^{10}\cdot 31^{4}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $36.97$
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:  $2, 3, 31$
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 \(a\))

$1$, $a$, $a^{2}$, $\frac{1}{3} a^{3}$, $\frac{1}{3} a^{4}$, $\frac{1}{9} a^{5} - \frac{1}{3} a^{2}$, $\frac{1}{9} a^{6}$, $\frac{1}{261} a^{7} + \frac{8}{261} a^{6} + \frac{7}{261} a^{5} - \frac{1}{29} a^{4} - \frac{10}{87} a^{3} + \frac{5}{87} a^{2} - \frac{8}{29} a + \frac{10}{29}$

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:  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:  \( 2961.55985368 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$F_8:C_3$ (as 8T36):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 168
The 8 conjugacy class representatives for $C_2^3:(C_7: C_3)$
Character table for $C_2^3:(C_7: C_3)$

Intermediate fields

The extension is primitive: there are no intermediate fields between this field and $\Q$.

Sibling fields

Degree 14 sibling: data not computed
Degree 24 sibling: data not computed
Degree 28 sibling: data not computed
Degree 42 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 R ${\href{/LocalNumberField/5.7.0.1}{7} }{,}\,{\href{/LocalNumberField/5.1.0.1}{1} }$ ${\href{/LocalNumberField/7.7.0.1}{7} }{,}\,{\href{/LocalNumberField/7.1.0.1}{1} }$ ${\href{/LocalNumberField/11.6.0.1}{6} }{,}\,{\href{/LocalNumberField/11.2.0.1}{2} }$ ${\href{/LocalNumberField/13.7.0.1}{7} }{,}\,{\href{/LocalNumberField/13.1.0.1}{1} }$ ${\href{/LocalNumberField/17.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/17.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/19.6.0.1}{6} }{,}\,{\href{/LocalNumberField/19.2.0.1}{2} }$ ${\href{/LocalNumberField/23.6.0.1}{6} }{,}\,{\href{/LocalNumberField/23.2.0.1}{2} }$ ${\href{/LocalNumberField/29.6.0.1}{6} }{,}\,{\href{/LocalNumberField/29.2.0.1}{2} }$ R ${\href{/LocalNumberField/37.6.0.1}{6} }{,}\,{\href{/LocalNumberField/37.2.0.1}{2} }$ ${\href{/LocalNumberField/41.7.0.1}{7} }{,}\,{\href{/LocalNumberField/41.1.0.1}{1} }$ ${\href{/LocalNumberField/43.7.0.1}{7} }{,}\,{\href{/LocalNumberField/43.1.0.1}{1} }$ ${\href{/LocalNumberField/47.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/47.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/53.6.0.1}{6} }{,}\,{\href{/LocalNumberField/53.2.0.1}{2} }$ ${\href{/LocalNumberField/59.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/59.1.0.1}{1} }^{2}$

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$$\Q_{2}$$x + 1$$1$$1$$0$Trivial$[\ ]$
2.7.6.1$x^{7} - 2$$7$$1$$6$$C_7:C_3$$[\ ]_{7}^{3}$
$3$3.2.1.1$x^{2} - 3$$2$$1$$1$$C_2$$[\ ]_{2}$
3.6.9.1$x^{6} + 3 x^{4} + 15$$6$$1$$9$$C_6$$[2]_{2}$
$31$31.2.0.1$x^{2} - x + 12$$1$$2$$0$$C_2$$[\ ]^{2}$
31.6.4.3$x^{6} + 713 x^{3} + 138384$$3$$2$$4$$C_6$$[\ ]_{3}^{2}$

Artin representations

Label Dimension Conductor Defining polynomial of Artin field $G$ Ind $\chi(c)$
* 1.1.1t1.1c1$1$ $1$ $x$ $C_1$ $1$ $1$
1.3e2_31.3t1.2c1$1$ $ 3^{2} \cdot 31 $ $x^{3} - 93 x - 217$ $C_3$ (as 3T1) $0$ $1$
1.3e2_31.3t1.2c2$1$ $ 3^{2} \cdot 31 $ $x^{3} - 93 x - 217$ $C_3$ (as 3T1) $0$ $1$
3.2e3_3e4_31e2.7t3.1c1$3$ $ 2^{3} \cdot 3^{4} \cdot 31^{2}$ $x^{7} - 18 x^{5} - 18 x^{4} + 60 x^{3} + 96 x^{2} + 44 x + 6$ $C_7:C_3$ (as 7T3) $0$ $3$
3.2e3_3e4_31e2.7t3.1c2$3$ $ 2^{3} \cdot 3^{4} \cdot 31^{2}$ $x^{7} - 18 x^{5} - 18 x^{4} + 60 x^{3} + 96 x^{2} + 44 x + 6$ $C_7:C_3$ (as 7T3) $0$ $3$
* 7.2e6_3e10_31e4.8t36.2c1$7$ $ 2^{6} \cdot 3^{10} \cdot 31^{4}$ $x^{8} - 3 x^{7} + 6 x^{6} + 30 x^{5} - 18 x^{4} - 90 x^{3} + 198 x^{2} - 162 x + 54$ $C_2^3:(C_7: C_3)$ (as 8T36) $1$ $-1$
7.2e6_3e11_31e5.24t283.2c1$7$ $ 2^{6} \cdot 3^{11} \cdot 31^{5}$ $x^{8} - 3 x^{7} + 6 x^{6} + 30 x^{5} - 18 x^{4} - 90 x^{3} + 198 x^{2} - 162 x + 54$ $C_2^3:(C_7: C_3)$ (as 8T36) $0$ $-1$
7.2e6_3e11_31e5.24t283.2c2$7$ $ 2^{6} \cdot 3^{11} \cdot 31^{5}$ $x^{8} - 3 x^{7} + 6 x^{6} + 30 x^{5} - 18 x^{4} - 90 x^{3} + 198 x^{2} - 162 x + 54$ $C_2^3:(C_7: C_3)$ (as 8T36) $0$ $-1$

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 *.