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Properties

Label 8.0.2101386547456.12
Degree $8$
Signature $[0, 4]$
Discriminant $2^{8}\cdot 7^{4}\cdot 43^{4}$
Root discriminant $34.70$
Ramified primes $2, 7, 43$
Class number $4$
Class group $[2, 2]$
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![153, 16, -94, 4, 34, -16, 2, -2, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^8 - 2*x^7 + 2*x^6 - 16*x^5 + 34*x^4 + 4*x^3 - 94*x^2 + 16*x + 153)
 
gp: K = bnfinit(x^8 - 2*x^7 + 2*x^6 - 16*x^5 + 34*x^4 + 4*x^3 - 94*x^2 + 16*x + 153, 1)
 

Normalized defining polynomial

\( x^{8} - 2 x^{7} + 2 x^{6} - 16 x^{5} + 34 x^{4} + 4 x^{3} - 94 x^{2} + 16 x + 153 \)

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:  \(2101386547456=2^{8}\cdot 7^{4}\cdot 43^{4}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $34.70$
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:  $2, 7, 43$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $\frac{1}{40187} a^{7} + \frac{2274}{40187} a^{6} - \frac{8497}{40187} a^{5} - \frac{9241}{40187} a^{4} - \frac{14681}{40187} a^{3} - \frac{18555}{40187} a^{2} + \frac{5263}{40187} a + \frac{2878}{40187}$

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

Class group and class number

$C_{2}\times C_{2}$, which has order $4$

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:  \( \frac{2421}{40187} a^{7} - \frac{265}{40187} a^{6} + \frac{4507}{40187} a^{5} - \frac{28489}{40187} a^{4} + \frac{22794}{40187} a^{3} + \frac{47598}{40187} a^{2} - \frac{118117}{40187} a - \frac{185648}{40187} \),  \( a - 2 \),  \( \frac{34238}{40187} a^{7} - \frac{65381}{40187} a^{6} - \frac{6593}{40187} a^{5} - \frac{81481}{40187} a^{4} + \frac{412788}{40187} a^{3} + \frac{150754}{40187} a^{2} - \frac{2817004}{40187} a + \frac{2811530}{40187} \)
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 574.051605692 \)
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 ${\href{/LocalNumberField/3.7.0.1}{7} }{,}\,{\href{/LocalNumberField/3.1.0.1}{1} }$ ${\href{/LocalNumberField/5.6.0.1}{6} }{,}\,{\href{/LocalNumberField/5.2.0.1}{2} }$ R ${\href{/LocalNumberField/11.6.0.1}{6} }{,}\,{\href{/LocalNumberField/11.2.0.1}{2} }$ ${\href{/LocalNumberField/13.6.0.1}{6} }{,}\,{\href{/LocalNumberField/13.2.0.1}{2} }$ ${\href{/LocalNumberField/17.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/17.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/19.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/19.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/23.6.0.1}{6} }{,}\,{\href{/LocalNumberField/23.2.0.1}{2} }$ ${\href{/LocalNumberField/29.6.0.1}{6} }{,}\,{\href{/LocalNumberField/29.2.0.1}{2} }$ ${\href{/LocalNumberField/31.7.0.1}{7} }{,}\,{\href{/LocalNumberField/31.1.0.1}{1} }$ ${\href{/LocalNumberField/37.6.0.1}{6} }{,}\,{\href{/LocalNumberField/37.2.0.1}{2} }$ ${\href{/LocalNumberField/41.7.0.1}{7} }{,}\,{\href{/LocalNumberField/41.1.0.1}{1} }$ R ${\href{/LocalNumberField/47.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/47.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/53.7.0.1}{7} }{,}\,{\href{/LocalNumberField/53.1.0.1}{1} }$ ${\href{/LocalNumberField/59.6.0.1}{6} }{,}\,{\href{/LocalNumberField/59.2.0.1}{2} }$

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$2.8.8.13$x^{8} + 2 x + 2$$8$$1$$8$$C_2^3:(C_7: C_3)$$[8/7, 8/7, 8/7]_{7}^{3}$
$7$$\Q_{7}$$x + 2$$1$$1$$0$Trivial$[\ ]$
$\Q_{7}$$x + 2$$1$$1$$0$Trivial$[\ ]$
7.3.2.3$x^{3} - 28$$3$$1$$2$$C_3$$[\ ]_{3}$
7.3.2.3$x^{3} - 28$$3$$1$$2$$C_3$$[\ ]_{3}$
$43$$\Q_{43}$$x + 9$$1$$1$$0$Trivial$[\ ]$
$\Q_{43}$$x + 9$$1$$1$$0$Trivial$[\ ]$
43.3.2.1$x^{3} - 43$$3$$1$$2$$C_3$$[\ ]_{3}$
43.3.2.1$x^{3} - 43$$3$$1$$2$$C_3$$[\ ]_{3}$

Artin representations

Label Dimension Conductor Defining polynomial of Artin field $G$ Ind $\chi(c)$
* 1.1.1t1.1c1$1$ $1$ $x$ $C_1$ $1$ $1$
1.7_43.3t1.2c1$1$ $ 7 \cdot 43 $ $x^{3} - x^{2} - 100 x + 379$ $C_3$ (as 3T1) $0$ $1$
1.7_43.3t1.2c2$1$ $ 7 \cdot 43 $ $x^{3} - x^{2} - 100 x + 379$ $C_3$ (as 3T1) $0$ $1$
3.2e3_7e2_43e2.7t3.1c1$3$ $ 2^{3} \cdot 7^{2} \cdot 43^{2}$ $x^{7} - x^{6} - 25 x^{5} + 49 x^{4} + 131 x^{3} - 415 x^{2} + 281 x + 7$ $C_7:C_3$ (as 7T3) $0$ $3$
3.2e3_7e2_43e2.7t3.1c2$3$ $ 2^{3} \cdot 7^{2} \cdot 43^{2}$ $x^{7} - x^{6} - 25 x^{5} + 49 x^{4} + 131 x^{3} - 415 x^{2} + 281 x + 7$ $C_7:C_3$ (as 7T3) $0$ $3$
* 7.2e8_7e4_43e4.8t36.1c1$7$ $ 2^{8} \cdot 7^{4} \cdot 43^{4}$ $x^{8} - 2 x^{7} + 2 x^{6} - 16 x^{5} + 34 x^{4} + 4 x^{3} - 94 x^{2} + 16 x + 153$ $C_2^3:(C_7: C_3)$ (as 8T36) $1$ $-1$
7.2e8_7e5_43e5.24t283.1c1$7$ $ 2^{8} \cdot 7^{5} \cdot 43^{5}$ $x^{8} - 2 x^{7} + 2 x^{6} - 16 x^{5} + 34 x^{4} + 4 x^{3} - 94 x^{2} + 16 x + 153$ $C_2^3:(C_7: C_3)$ (as 8T36) $0$ $-1$
7.2e8_7e5_43e5.24t283.1c2$7$ $ 2^{8} \cdot 7^{5} \cdot 43^{5}$ $x^{8} - 2 x^{7} + 2 x^{6} - 16 x^{5} + 34 x^{4} + 4 x^{3} - 94 x^{2} + 16 x + 153$ $C_2^3:(C_7: C_3)$ (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 *.