Properties

Label 16.0.15244671129...5625.1
Degree $16$
Signature $[0, 8]$
Discriminant $3^{8}\cdot 5^{8}\cdot 29^{6}$
Root discriminant $13.69$
Ramified primes $3, 5, 29$
Class number $1$
Class group Trivial
Galois group $D_8:C_2$ (as 16T44)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![31, -100, 194, -262, 292, -233, 163, -55, 0, 40, -32, 24, -6, 2, 3, -1, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^16 - x^15 + 3*x^14 + 2*x^13 - 6*x^12 + 24*x^11 - 32*x^10 + 40*x^9 - 55*x^7 + 163*x^6 - 233*x^5 + 292*x^4 - 262*x^3 + 194*x^2 - 100*x + 31)
 
gp: K = bnfinit(x^16 - x^15 + 3*x^14 + 2*x^13 - 6*x^12 + 24*x^11 - 32*x^10 + 40*x^9 - 55*x^7 + 163*x^6 - 233*x^5 + 292*x^4 - 262*x^3 + 194*x^2 - 100*x + 31, 1)
 

Normalized defining polynomial

\( x^{16} - x^{15} + 3 x^{14} + 2 x^{13} - 6 x^{12} + 24 x^{11} - 32 x^{10} + 40 x^{9} - 55 x^{7} + 163 x^{6} - 233 x^{5} + 292 x^{4} - 262 x^{3} + 194 x^{2} - 100 x + 31 \)

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:  \(1524467112922265625=3^{8}\cdot 5^{8}\cdot 29^{6}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $13.69$
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:  $3, 5, 29$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $\frac{1}{133} a^{14} - \frac{8}{133} a^{13} - \frac{2}{19} a^{12} + \frac{1}{7} a^{11} - \frac{48}{133} a^{10} + \frac{37}{133} a^{9} + \frac{3}{19} a^{8} - \frac{15}{133} a^{7} + \frac{5}{19} a^{6} - \frac{3}{133} a^{5} + \frac{23}{133} a^{4} - \frac{6}{19} a^{3} - \frac{29}{133} a^{2} - \frac{52}{133} a + \frac{15}{133}$, $\frac{1}{76668781} a^{15} + \frac{150301}{76668781} a^{14} + \frac{27437468}{76668781} a^{13} - \frac{222571}{4035199} a^{12} - \frac{12197516}{76668781} a^{11} + \frac{3671359}{10952683} a^{10} - \frac{32556878}{76668781} a^{9} + \frac{32599349}{76668781} a^{8} - \frac{13208347}{76668781} a^{7} - \frac{25672195}{76668781} a^{6} - \frac{16018554}{76668781} a^{5} - \frac{197110}{76668781} a^{4} - \frac{12277924}{76668781} a^{3} - \frac{31432227}{76668781} a^{2} - \frac{4906186}{10952683} a + \frac{1634956}{4035199}$

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:  \( \frac{191889}{1564669} a^{15} - \frac{105684}{1564669} a^{14} + \frac{331734}{1564669} a^{13} + \frac{678039}{1564669} a^{12} - \frac{1131321}{1564669} a^{11} + \frac{3470598}{1564669} a^{10} - \frac{3106238}{1564669} a^{9} + \frac{2792540}{1564669} a^{8} + \frac{4852466}{1564669} a^{7} - \frac{10499636}{1564669} a^{6} + \frac{21035803}{1564669} a^{5} - \frac{22649472}{1564669} a^{4} + \frac{23940733}{1564669} a^{3} - \frac{15839643}{1564669} a^{2} + \frac{8651129}{1564669} a - \frac{936381}{1564669} \) (order $6$)
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:  \( 688.925584956 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$D_8:C_2$ (as 16T44):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 32
The 14 conjugacy class representatives for $D_8:C_2$
Character table for $D_8:C_2$

Intermediate fields

\(\Q(\sqrt{5}) \), \(\Q(\sqrt{-15}) \), \(\Q(\sqrt{-3}) \), 4.4.725.1, 4.0.6525.1, \(\Q(\sqrt{-3}, \sqrt{5})\), 8.0.42575625.1

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

Frobenius cycle types

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59
Cycle type ${\href{/LocalNumberField/2.8.0.1}{8} }^{2}$ R R ${\href{/LocalNumberField/7.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/11.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/13.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/17.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/19.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/19.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/23.4.0.1}{4} }^{4}$ R ${\href{/LocalNumberField/31.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/31.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/37.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/41.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/43.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/47.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/53.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/59.4.0.1}{4} }^{4}$

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
3Data not computed
$5$5.8.4.1$x^{8} + 10 x^{6} + 125 x^{4} + 2500$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$
5.8.4.1$x^{8} + 10 x^{6} + 125 x^{4} + 2500$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$
$29$29.4.2.2$x^{4} - 29 x^{2} + 2523$$2$$2$$2$$C_4$$[\ ]_{2}^{2}$
29.4.0.1$x^{4} - x + 19$$1$$4$$0$$C_4$$[\ ]^{4}$
29.8.4.1$x^{8} + 31958 x^{4} - 24389 x^{2} + 255328441$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$