Properties

Label 8.0.1721829632.1
Degree $8$
Signature $[0, 4]$
Discriminant $2^{8}\cdot 17^{3}\cdot 37^{2}$
Root discriminant $14.27$
Ramified primes $2, 17, 37$
Class number $1$
Class group Trivial
Galois group $Z_8 : Z_8^\times$ (as 8T15)

Related objects

Downloads

Learn more about

Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![53, 74, -36, -72, 16, 24, -5, -2, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^8 - 2*x^7 - 5*x^6 + 24*x^5 + 16*x^4 - 72*x^3 - 36*x^2 + 74*x + 53)
 
gp: K = bnfinit(x^8 - 2*x^7 - 5*x^6 + 24*x^5 + 16*x^4 - 72*x^3 - 36*x^2 + 74*x + 53, 1)
 

Normalized defining polynomial

\( x^{8} - 2 x^{7} - 5 x^{6} + 24 x^{5} + 16 x^{4} - 72 x^{3} - 36 x^{2} + 74 x + 53 \)

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:  \(1721829632=2^{8}\cdot 17^{3}\cdot 37^{2}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $14.27$
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:  $2, 17, 37$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $\frac{1}{2533} a^{7} + \frac{1005}{2533} a^{6} - \frac{1170}{2533} a^{5} - \frac{321}{2533} a^{4} + \frac{993}{2533} a^{3} - \frac{656}{2533} a^{2} + \frac{485}{2533} a - \frac{400}{2533}$

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:  \( -\frac{87}{149} a^{7} + \frac{326}{149} a^{6} - \frac{126}{149} a^{5} - \frac{1873}{149} a^{4} + \frac{1817}{149} a^{3} + \frac{3283}{149} a^{2} - \frac{2263}{149} a - \frac{2897}{149} \) (order $4$)
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:  \( 42.3287213263 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_8:C_2^2$ (as 8T15):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 32
The 11 conjugacy class representatives for $Z_8 : Z_8^\times$
Character table for $Z_8 : Z_8^\times$

Intermediate fields

\(\Q(\sqrt{-1}) \), 4.0.272.1

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 16 siblings: data not computed
Arithmetically equvalently sibling: 8.0.1721829632.2

Frobenius cycle types

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59
Cycle type R ${\href{/LocalNumberField/3.8.0.1}{8} }$ ${\href{/LocalNumberField/5.2.0.1}{2} }^{3}{,}\,{\href{/LocalNumberField/5.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/7.8.0.1}{8} }$ ${\href{/LocalNumberField/11.8.0.1}{8} }$ ${\href{/LocalNumberField/13.4.0.1}{4} }^{2}$ R ${\href{/LocalNumberField/19.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/23.8.0.1}{8} }$ ${\href{/LocalNumberField/29.2.0.1}{2} }^{3}{,}\,{\href{/LocalNumberField/29.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/31.8.0.1}{8} }$ R ${\href{/LocalNumberField/41.2.0.1}{2} }^{3}{,}\,{\href{/LocalNumberField/41.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/43.4.0.1}{4} }^{2}$ ${\href{/LocalNumberField/47.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/53.1.0.1}{1} }^{8}$ ${\href{/LocalNumberField/59.4.0.1}{4} }^{2}$

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$$[2]^{4}$
$17$$\Q_{17}$$x + 3$$1$$1$$0$Trivial$[\ ]$
$\Q_{17}$$x + 3$$1$$1$$0$Trivial$[\ ]$
17.2.1.1$x^{2} - 17$$2$$1$$1$$C_2$$[\ ]_{2}$
17.4.2.1$x^{4} + 85 x^{2} + 2601$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
37Data not computed

Artin representations

Label Dimension Conductor Defining polynomial of Artin field $G$ Ind $\chi(c)$
* 1.1.1t1.1c1$1$ $1$ $x$ $C_1$ $1$ $1$
1.17.2t1.1c1$1$ $ 17 $ $x^{2} - x - 4$ $C_2$ (as 2T1) $1$ $1$
1.2e2_37.2t1.1c1$1$ $ 2^{2} \cdot 37 $ $x^{2} + 37$ $C_2$ (as 2T1) $1$ $-1$
1.2e2_17_37.2t1.1c1$1$ $ 2^{2} \cdot 17 \cdot 37 $ $x^{2} + 629$ $C_2$ (as 2T1) $1$ $-1$
1.37.2t1.1c1$1$ $ 37 $ $x^{2} - x - 9$ $C_2$ (as 2T1) $1$ $1$
1.17_37.2t1.1c1$1$ $ 17 \cdot 37 $ $x^{2} - x - 157$ $C_2$ (as 2T1) $1$ $1$
* 1.2e2.2t1.1c1$1$ $ 2^{2}$ $x^{2} + 1$ $C_2$ (as 2T1) $1$ $-1$
1.2e2_17.2t1.1c1$1$ $ 2^{2} \cdot 17 $ $x^{2} + 17$ $C_2$ (as 2T1) $1$ $-1$
* 2.2e2_17.4t3.1c1$2$ $ 2^{2} \cdot 17 $ $x^{4} + x^{2} - 2 x + 1$ $D_{4}$ (as 4T3) $1$ $0$
2.2e2_17_37e2.4t3.1c1$2$ $ 2^{2} \cdot 17 \cdot 37^{2}$ $x^{4} - 2 x^{3} - 17 x^{2} + 18 x + 1450$ $D_{4}$ (as 4T3) $1$ $0$
* 4.2e4_17e2_37e2.8t15.1c1$4$ $ 2^{4} \cdot 17^{2} \cdot 37^{2}$ $x^{8} - 2 x^{7} - 5 x^{6} + 24 x^{5} + 16 x^{4} - 72 x^{3} - 36 x^{2} + 74 x + 53$ $Z_8 : Z_8^\times$ (as 8T15) $1$ $0$

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 *.