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Properties

Label 16.0.34789235097...0000.4
Degree $16$
Signature $[0, 8]$
Discriminant $2^{40}\cdot 3^{4}\cdot 5^{8}$
Root discriminant $16.65$
Ramified primes $2, 3, 5$
Class number $1$
Class group Trivial
Galois group $Q_8 : C_2^2$ (as 16T23)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![41, -280, 868, -1528, 1668, -1224, 812, -692, 609, -408, 240, -116, 70, -32, 16, -4, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^16 - 4*x^15 + 16*x^14 - 32*x^13 + 70*x^12 - 116*x^11 + 240*x^10 - 408*x^9 + 609*x^8 - 692*x^7 + 812*x^6 - 1224*x^5 + 1668*x^4 - 1528*x^3 + 868*x^2 - 280*x + 41)
 
gp: K = bnfinit(x^16 - 4*x^15 + 16*x^14 - 32*x^13 + 70*x^12 - 116*x^11 + 240*x^10 - 408*x^9 + 609*x^8 - 692*x^7 + 812*x^6 - 1224*x^5 + 1668*x^4 - 1528*x^3 + 868*x^2 - 280*x + 41, 1)
 

Normalized defining polynomial

\( x^{16} - 4 x^{15} + 16 x^{14} - 32 x^{13} + 70 x^{12} - 116 x^{11} + 240 x^{10} - 408 x^{9} + 609 x^{8} - 692 x^{7} + 812 x^{6} - 1224 x^{5} + 1668 x^{4} - 1528 x^{3} + 868 x^{2} - 280 x + 41 \)

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

Invariants

Degree:  $16$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[0, 8]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(34789235097600000000=2^{40}\cdot 3^{4}\cdot 5^{8}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $16.65$
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:  $2, 3, 5$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $\frac{1}{5} a^{14} + \frac{2}{5} a^{12} + \frac{1}{5} a^{11} + \frac{1}{5} a^{10} - \frac{1}{5} a^{9} + \frac{2}{5} a^{8} - \frac{1}{5} a^{7} + \frac{2}{5} a^{6} - \frac{1}{5} a^{4} + \frac{2}{5} a^{3} - \frac{1}{5} a - \frac{1}{5}$, $\frac{1}{12814938817126075} a^{15} - \frac{277306652097532}{12814938817126075} a^{14} - \frac{2890742412829118}{12814938817126075} a^{13} - \frac{603499170410554}{1830705545303725} a^{12} - \frac{753030263032608}{1830705545303725} a^{11} + \frac{6251326596600172}{12814938817126075} a^{10} - \frac{3961296714212456}{12814938817126075} a^{9} + \frac{1219305629115548}{2562987763425215} a^{8} - \frac{3237466598265121}{12814938817126075} a^{7} + \frac{590289731981943}{1830705545303725} a^{6} - \frac{323850675168118}{1830705545303725} a^{5} + \frac{2705816899151304}{12814938817126075} a^{4} - \frac{5829069885270039}{12814938817126075} a^{3} + \frac{5904651777886154}{12814938817126075} a^{2} + \frac{3556899447373381}{12814938817126075} a - \frac{1698745238601518}{12814938817126075}$

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:  $7$
magma: UnitRank(K);
 
sage: UK.rank()
 
gp: K.fu
 
Torsion generator:  \( -\frac{16182679727161}{53174019988075} a^{15} + \frac{47767745119552}{53174019988075} a^{14} - \frac{202875350911727}{53174019988075} a^{13} + \frac{41154305174044}{7596288569725} a^{12} - \frac{108204352943612}{7596288569725} a^{11} + \frac{983172238801758}{53174019988075} a^{10} - \frac{2581886008157034}{53174019988075} a^{9} + \frac{710866753188642}{10634803997615} a^{8} - \frac{5202632442080394}{53174019988075} a^{7} + \frac{643411391713902}{7596288569725} a^{6} - \frac{942078457355252}{7596288569725} a^{5} + \frac{11362061593865581}{53174019988075} a^{4} - \frac{12741978292917721}{53174019988075} a^{3} + \frac{7327140444972631}{53174019988075} a^{2} - \frac{1960602245729041}{53174019988075} a + \frac{82351755010748}{53174019988075} \) (order $8$)
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:  \( 6775.13950499 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$Q_8:C_2^2$ (as 16T23):

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 $Q_8 : C_2^2$
Character table for $Q_8 : C_2^2$

Intermediate fields

\(\Q(\sqrt{5}) \), \(\Q(\sqrt{-1}) \), \(\Q(\sqrt{-10}) \), \(\Q(\sqrt{2}) \), \(\Q(\sqrt{-5}) \), \(\Q(\sqrt{-2}) \), \(\Q(\sqrt{10}) \), \(\Q(\sqrt{-2}, \sqrt{-5})\), \(\Q(i, \sqrt{5})\), \(\Q(\sqrt{2}, \sqrt{-5})\), \(\Q(\sqrt{-2}, \sqrt{5})\), \(\Q(\zeta_{8})\), \(\Q(\sqrt{2}, \sqrt{5})\), \(\Q(i, \sqrt{10})\), 8.0.40960000.1, 8.0.368640000.1 x2, 8.0.5898240000.4 x2

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 R ${\href{/LocalNumberField/7.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/11.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/13.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/17.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/19.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/23.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/29.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/31.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/37.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/41.2.0.1}{2} }^{4}{,}\,{\href{/LocalNumberField/41.1.0.1}{1} }^{8}$ ${\href{/LocalNumberField/43.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/47.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/53.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/59.2.0.1}{2} }^{8}$

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
2Data not computed
$3$3.4.2.2$x^{4} - 3 x^{2} + 18$$2$$2$$2$$C_4$$[\ ]_{2}^{2}$
3.4.2.2$x^{4} - 3 x^{2} + 18$$2$$2$$2$$C_4$$[\ ]_{2}^{2}$
3.4.0.1$x^{4} - x + 2$$1$$4$$0$$C_4$$[\ ]^{4}$
3.4.0.1$x^{4} - x + 2$$1$$4$$0$$C_4$$[\ ]^{4}$
$5$5.4.2.1$x^{4} + 15 x^{2} + 100$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
5.4.2.1$x^{4} + 15 x^{2} + 100$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
5.4.2.1$x^{4} + 15 x^{2} + 100$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
5.4.2.1$x^{4} + 15 x^{2} + 100$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$