Properties

Label 8.2.11977812992.1
Degree $8$
Signature $[2, 3]$
Discriminant $-\,2^{10}\cdot 227^{3}$
Root discriminant $18.19$
Ramified primes $2, 227$
Class number $1$
Class group Trivial
Galois group $\textrm{GL(2,3)}$ (as 8T23)

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Show commands for: SageMath / Pari/GP / Magma

sage: x = polygen(QQ); K.<a> = NumberField(x^8 - 2*x^7 - 4*x^5 - 6*x^4 - 10*x^3 + 6*x^2 + 4*x - 2)
 
gp: K = bnfinit(x^8 - 2*x^7 - 4*x^5 - 6*x^4 - 10*x^3 + 6*x^2 + 4*x - 2, 1)
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![-2, 4, 6, -10, -6, -4, 0, -2, 1]);
 

Normalized defining polynomial

\( x^{8} - 2 x^{7} - 4 x^{5} - 6 x^{4} - 10 x^{3} + 6 x^{2} + 4 x - 2 \)

sage: K.defining_polynomial()
 
gp: K.pol
 
magma: DefiningPolynomial(K);
 

Invariants

Degree:  $8$
sage: K.degree()
 
gp: poldegree(K.pol)
 
magma: Degree(K);
 
Signature:  $[2, 3]$
sage: K.signature()
 
gp: K.sign
 
magma: Signature(K);
 
Discriminant:  \(-11977812992=-\,2^{10}\cdot 227^{3}\)
sage: K.disc()
 
gp: K.disc
 
magma: Discriminant(Integers(K));
 
Root discriminant:  $18.19$
sage: (K.disc().abs())^(1./K.degree())
 
gp: abs(K.disc)^(1/poldegree(K.pol))
 
magma: Abs(Discriminant(Integers(K)))^(1/Degree(K));
 
Ramified primes:  $2, 227$
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
magma: PrimeDivisors(Discriminant(Integers(K)));
 
$|\Aut(K/\Q)|$:  $2$
This field is not Galois over $\Q$.
This is not a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $\frac{1}{139} a^{7} + \frac{23}{139} a^{6} + \frac{19}{139} a^{5} + \frac{54}{139} a^{4} - \frac{46}{139} a^{3} - \frac{48}{139} a^{2} + \frac{57}{139} a + \frac{39}{139}$

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

Class group and class number

Trivial group, which has order $1$

sage: K.class_group().invariants()
 
gp: K.clgp
 
magma: ClassGroup(K);
 

Unit group

sage: UK = K.unit_group()
 
magma: UK, f := UnitGroup(K);
 
Rank:  $4$
sage: UK.rank()
 
gp: K.fu
 
magma: UnitRank(K);
 
Torsion generator:  \( -1 \) (order $2$)
sage: UK.torsion_generator()
 
gp: K.tu[2]
 
magma: K!f(TU.1) where TU,f is TorsionUnitGroup(K);
 
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
sage: UK.fundamental_units()
 
gp: K.fu
 
magma: [K!f(g): g in Generators(UK)];
 
Regulator:  \( 107.131591344 \)
sage: K.regulator()
 
gp: K.reg
 
magma: Regulator(K);
 

Galois group

$\GL(2,3)$ (as 8T23):

sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
magma: GaloisGroup(K);
 
A solvable group of order 48
The 8 conjugacy class representatives for $\textrm{GL(2,3)}$
Character table for $\textrm{GL(2,3)}$

Intermediate fields

4.2.3632.1

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

Sibling fields

Degree 16 sibling: Deg 16
Degree 24 sibling: Deg 24
Arithmetically equvalently sibling: 8.2.11977812992.2

Frobenius cycle types

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59
Cycle type R ${\href{/LocalNumberField/3.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/5.8.0.1}{8} }$ ${\href{/LocalNumberField/7.6.0.1}{6} }{,}\,{\href{/LocalNumberField/7.2.0.1}{2} }$ ${\href{/LocalNumberField/11.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/11.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/13.2.0.1}{2} }^{3}{,}\,{\href{/LocalNumberField/13.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/17.8.0.1}{8} }$ ${\href{/LocalNumberField/19.6.0.1}{6} }{,}\,{\href{/LocalNumberField/19.2.0.1}{2} }$ ${\href{/LocalNumberField/23.6.0.1}{6} }{,}\,{\href{/LocalNumberField/23.2.0.1}{2} }$ ${\href{/LocalNumberField/29.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/29.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/31.8.0.1}{8} }$ ${\href{/LocalNumberField/37.8.0.1}{8} }$ ${\href{/LocalNumberField/41.8.0.1}{8} }$ ${\href{/LocalNumberField/43.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/43.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/47.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/53.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/53.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/59.6.0.1}{6} }{,}\,{\href{/LocalNumberField/59.2.0.1}{2} }$

In the table, R denotes a ramified prime. Cycle lengths which are repeated in a cycle type are indicated by exponents.

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]])
 
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];
 

Local algebras for ramified primes

$p$LabelPolynomial $e$ $f$ $c$ Galois group Slope content
$2$2.8.10.3$x^{8} + 4 x^{2} + 20$$8$$1$$10$$\textrm{GL(2,3)}$$[4/3, 4/3, 3/2]_{3}^{2}$
227Data not computed

Artin representations

Label Dimension Conductor Defining polynomial of Artin field $G$ Ind $\chi(c)$
* 1.1.1t1.a.a$1$ $1$ $x$ $C_1$ $1$ $1$
1.227.2t1.a.a$1$ $ 227 $ $x^{2} - x + 57$ $C_2$ (as 2T1) $1$ $-1$
2.908.3t2.a.a$2$ $ 2^{2} \cdot 227 $ $x^{3} - 4 x - 12$ $S_3$ (as 3T2) $1$ $0$
2.1816.24t22.a.a$2$ $ 2^{3} \cdot 227 $ $x^{8} - 2 x^{7} - 4 x^{5} - 6 x^{4} - 10 x^{3} + 6 x^{2} + 4 x - 2$ $\textrm{GL(2,3)}$ (as 8T23) $0$ $0$
2.1816.24t22.a.b$2$ $ 2^{3} \cdot 227 $ $x^{8} - 2 x^{7} - 4 x^{5} - 6 x^{4} - 10 x^{3} + 6 x^{2} + 4 x - 2$ $\textrm{GL(2,3)}$ (as 8T23) $0$ $0$
3.824464.6t8.a.a$3$ $ 2^{4} \cdot 227^{2}$ $x^{4} - 2 x^{3} - 2 x + 2$ $S_4$ (as 4T5) $1$ $-1$
* 3.3632.4t5.a.a$3$ $ 2^{4} \cdot 227 $ $x^{4} - 2 x^{3} - 2 x + 2$ $S_4$ (as 4T5) $1$ $1$
* 4.3297856.8t23.a.a$4$ $ 2^{6} \cdot 227^{2}$ $x^{8} - 2 x^{7} - 4 x^{5} - 6 x^{4} - 10 x^{3} + 6 x^{2} + 4 x - 2$ $\textrm{GL(2,3)}$ (as 8T23) $1$ $0$

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 *.