Properties

Label 8.0.424030464.1
Degree $8$
Signature $[0, 4]$
Discriminant $2^{8}\cdot 3^{4}\cdot 11^{2}\cdot 13^{2}$
Root discriminant $11.98$
Ramified primes $2, 3, 11, 13$
Class number $1$
Class group Trivial
Galois group $C_2^3 : D_4 $ (as 8T22)

Related objects

Downloads

Learn more about

Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![73, 68, -17, -46, 15, 10, -5, -2, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^8 - 2*x^7 - 5*x^6 + 10*x^5 + 15*x^4 - 46*x^3 - 17*x^2 + 68*x + 73)
 
gp: K = bnfinit(x^8 - 2*x^7 - 5*x^6 + 10*x^5 + 15*x^4 - 46*x^3 - 17*x^2 + 68*x + 73, 1)
 

Normalized defining polynomial

\( x^{8} - 2 x^{7} - 5 x^{6} + 10 x^{5} + 15 x^{4} - 46 x^{3} - 17 x^{2} + 68 x + 73 \)

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:  \(424030464=2^{8}\cdot 3^{4}\cdot 11^{2}\cdot 13^{2}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $11.98$
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:  $2, 3, 11, 13$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $\frac{1}{35} a^{6} + \frac{8}{35} a^{5} + \frac{1}{5} a^{4} - \frac{9}{35} a^{3} + \frac{9}{35} a^{2} - \frac{9}{35} a + \frac{16}{35}$, $\frac{1}{1295} a^{7} + \frac{2}{259} a^{6} - \frac{292}{1295} a^{5} - \frac{55}{259} a^{4} + \frac{341}{1295} a^{3} - \frac{61}{1295} a^{2} - \frac{527}{1295} a - \frac{3}{1295}$

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

Class group and class number

Trivial group, which has order $1$

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:  \( \frac{58}{1295} a^{7} + \frac{62}{1295} a^{6} - \frac{72}{259} a^{5} - \frac{151}{1295} a^{4} + \frac{226}{259} a^{3} - \frac{86}{259} a^{2} - \frac{3889}{1295} a - \frac{1987}{1295} \) (order $12$)
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:  \( 55.4013718228 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$Q_8:C_2^2$ (as 8T22):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 32
The 17 conjugacy class representatives for $C_2^3 : D_4 $
Character table for $C_2^3 : D_4 $

Intermediate fields

\(\Q(\sqrt{-3}) \), \(\Q(\sqrt{3}) \), \(\Q(\sqrt{-1}) \), \(\Q(\zeta_{12})\)

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

Sibling fields

Galois closure: data not computed
Degree 8 siblings: data not computed
Degree 16 siblings: 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 ${\href{/LocalNumberField/5.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/7.2.0.1}{2} }^{4}$ R R ${\href{/LocalNumberField/17.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/19.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/23.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/29.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/31.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/37.2.0.1}{2} }^{2}{,}\,{\href{/LocalNumberField/37.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/41.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/43.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/47.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/53.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/59.4.0.1}{4} }^{2}$

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
$2$2.8.8.1$x^{8} + 28 x^{4} + 144$$2$$4$$8$$C_4\times C_2$$[2]^{4}$
$3$3.4.2.1$x^{4} + 9 x^{2} + 36$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
3.4.2.1$x^{4} + 9 x^{2} + 36$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
$11$11.4.2.2$x^{4} - 11 x^{2} + 847$$2$$2$$2$$C_4$$[\ ]_{2}^{2}$
11.4.0.1$x^{4} - x + 2$$1$$4$$0$$C_4$$[\ ]^{4}$
$13$$\Q_{13}$$x + 2$$1$$1$$0$Trivial$[\ ]$
$\Q_{13}$$x + 2$$1$$1$$0$Trivial$[\ ]$
13.2.1.2$x^{2} + 26$$2$$1$$1$$C_2$$[\ ]_{2}$
13.2.1.1$x^{2} - 13$$2$$1$$1$$C_2$$[\ ]_{2}$
13.2.0.1$x^{2} - x + 2$$1$$2$$0$$C_2$$[\ ]^{2}$

Artin representations

Label Dimension Conductor Defining polynomial of Artin field $G$ Ind $\chi(c)$
* 1.1.1t1.1c1$1$ $1$ $x$ $C_1$ $1$ $1$
1.13.2t1.1c1$1$ $ 13 $ $x^{2} - x - 3$ $C_2$ (as 2T1) $1$ $1$
1.3_11_13.2t1.1c1$1$ $ 3 \cdot 11 \cdot 13 $ $x^{2} - x - 107$ $C_2$ (as 2T1) $1$ $1$
1.3_11.2t1.1c1$1$ $ 3 \cdot 11 $ $x^{2} - x - 8$ $C_2$ (as 2T1) $1$ $1$
1.11.2t1.1c1$1$ $ 11 $ $x^{2} - x + 3$ $C_2$ (as 2T1) $1$ $-1$
1.11_13.2t1.1c1$1$ $ 11 \cdot 13 $ $x^{2} - x + 36$ $C_2$ (as 2T1) $1$ $-1$
* 1.3.2t1.1c1$1$ $ 3 $ $x^{2} - x + 1$ $C_2$ (as 2T1) $1$ $-1$
1.3_13.2t1.1c1$1$ $ 3 \cdot 13 $ $x^{2} - x + 10$ $C_2$ (as 2T1) $1$ $-1$
1.2e2_3_11_13.2t1.1c1$1$ $ 2^{2} \cdot 3 \cdot 11 \cdot 13 $ $x^{2} + 429$ $C_2$ (as 2T1) $1$ $-1$
1.2e2_3_11.2t1.1c1$1$ $ 2^{2} \cdot 3 \cdot 11 $ $x^{2} + 33$ $C_2$ (as 2T1) $1$ $-1$
1.2e2_13.2t1.1c1$1$ $ 2^{2} \cdot 13 $ $x^{2} + 13$ $C_2$ (as 2T1) $1$ $-1$
* 1.2e2.2t1.1c1$1$ $ 2^{2}$ $x^{2} + 1$ $C_2$ (as 2T1) $1$ $-1$
* 1.2e2_3.2t1.1c1$1$ $ 2^{2} \cdot 3 $ $x^{2} - 3$ $C_2$ (as 2T1) $1$ $1$
1.2e2_3_13.2t1.1c1$1$ $ 2^{2} \cdot 3 \cdot 13 $ $x^{2} - 39$ $C_2$ (as 2T1) $1$ $1$
1.2e2_11.2t1.1c1$1$ $ 2^{2} \cdot 11 $ $x^{2} - 11$ $C_2$ (as 2T1) $1$ $1$
1.2e2_11_13.2t1.1c1$1$ $ 2^{2} \cdot 11 \cdot 13 $ $x^{2} - 143$ $C_2$ (as 2T1) $1$ $1$
* 4.2e4_3e2_11e2_13e2.8t22.5c1$4$ $ 2^{4} \cdot 3^{2} \cdot 11^{2} \cdot 13^{2}$ $x^{8} - 2 x^{7} - 5 x^{6} + 10 x^{5} + 15 x^{4} - 46 x^{3} - 17 x^{2} + 68 x + 73$ $C_2^3 : D_4 $ (as 8T22) $1$ $0$

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 *.