Properties

Label 16.4.18244960011...2161.1
Degree $16$
Signature $[4, 6]$
Discriminant $13^{12}\cdot 23^{8}$
Root discriminant $32.83$
Ramified primes $13, 23$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group $D_4:C_4$ (as 16T26)

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magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![81, 0, -477, 0, 908, 0, -395, 0, -605, 0, 201, 0, 20, 0, -17, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^16 - 17*x^14 + 20*x^12 + 201*x^10 - 605*x^8 - 395*x^6 + 908*x^4 - 477*x^2 + 81)
 
gp: K = bnfinit(x^16 - 17*x^14 + 20*x^12 + 201*x^10 - 605*x^8 - 395*x^6 + 908*x^4 - 477*x^2 + 81, 1)
 

Normalized defining polynomial

\( x^{16} - 17 x^{14} + 20 x^{12} + 201 x^{10} - 605 x^{8} - 395 x^{6} + 908 x^{4} - 477 x^{2} + 81 \)

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

Invariants

Degree:  $16$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[4, 6]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(1824496001102094673202161=13^{12}\cdot 23^{8}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $32.83$
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:  $13, 23$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $\frac{1}{26} a^{8} - \frac{1}{2} a^{7} - \frac{1}{13} a^{6} - \frac{1}{2} a^{5} - \frac{5}{26} a^{4} - \frac{1}{2} a^{3} + \frac{3}{13} a^{2} - \frac{1}{2} a + \frac{9}{26}$, $\frac{1}{78} a^{9} - \frac{5}{26} a^{7} - \frac{1}{2} a^{6} - \frac{3}{13} a^{5} - \frac{11}{26} a^{3} - \frac{1}{2} a^{2} + \frac{11}{39} a - \frac{1}{2}$, $\frac{1}{78} a^{10} + \frac{5}{13} a^{6} - \frac{1}{2} a^{5} - \frac{5}{13} a^{4} + \frac{17}{39} a^{2} - \frac{7}{26}$, $\frac{1}{78} a^{11} + \frac{5}{13} a^{7} - \frac{1}{2} a^{6} - \frac{5}{13} a^{5} + \frac{17}{39} a^{3} - \frac{7}{26} a$, $\frac{1}{78} a^{12} - \frac{1}{2} a^{7} + \frac{5}{13} a^{6} + \frac{14}{39} a^{4} + \frac{11}{26} a^{2} - \frac{6}{13}$, $\frac{1}{78} a^{13} - \frac{3}{26} a^{7} - \frac{11}{78} a^{5} - \frac{1}{2} a^{4} - \frac{1}{13} a^{3} + \frac{1}{26} a - \frac{1}{2}$, $\frac{1}{1193166} a^{14} + \frac{2240}{596583} a^{12} + \frac{431}{1193166} a^{10} - \frac{3268}{198861} a^{8} - \frac{1}{2} a^{7} - \frac{67061}{1193166} a^{6} - \frac{1}{2} a^{5} + \frac{343177}{1193166} a^{4} - \frac{1}{2} a^{3} - \frac{413581}{1193166} a^{2} - \frac{12108}{66287}$, $\frac{1}{3579498} a^{15} - \frac{10817}{3579498} a^{13} - \frac{7433}{1789749} a^{11} - \frac{3268}{596583} a^{9} + \frac{1401451}{3579498} a^{7} + \frac{373771}{3579498} a^{5} - \frac{1}{2} a^{4} - \frac{122657}{1789749} a^{3} + \frac{72665}{397722} a$

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

Class group and class number

Trivial group, which has order $1$ (assuming GRH)

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

Unit group

magma: UK, f := UnitGroup(K);
 
sage: UK = K.unit_group()
 
Rank:  $9$
magma: UnitRank(K);
 
sage: UK.rank()
 
gp: K.fu
 
Torsion generator:  \( -1 \) (order $2$)
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 (assuming GRH)
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 752694.735162 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$D_4:C_4$ (as 16T26):

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 $D_4:C_4$
Character table for $D_4:C_4$

Intermediate fields

\(\Q(\sqrt{13}) \), 4.2.3887.1, 4.4.1162213.1, 4.2.50531.1, 8.2.58727785103.1, 8.2.347501687.1, 8.4.1350739057369.1

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 sibling: 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 ${\href{/LocalNumberField/2.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/3.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/5.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/7.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/11.8.0.1}{8} }^{2}$ R ${\href{/LocalNumberField/17.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/17.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/19.8.0.1}{8} }^{2}$ R ${\href{/LocalNumberField/29.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/31.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/37.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/41.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/43.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/43.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/47.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/53.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/59.4.0.1}{4} }^{4}$

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
$13$13.8.6.1$x^{8} - 13 x^{4} + 2704$$4$$2$$6$$C_4\times C_2$$[\ ]_{4}^{2}$
13.8.6.1$x^{8} - 13 x^{4} + 2704$$4$$2$$6$$C_4\times C_2$$[\ ]_{4}^{2}$
$23$23.2.1.1$x^{2} - 23$$2$$1$$1$$C_2$$[\ ]_{2}$
23.2.1.1$x^{2} - 23$$2$$1$$1$$C_2$$[\ ]_{2}$
23.4.2.1$x^{4} + 299 x^{2} + 25921$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
23.4.2.1$x^{4} + 299 x^{2} + 25921$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
23.4.2.1$x^{4} + 299 x^{2} + 25921$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$