Properties

Label 16.4.99768683774...4544.2
Degree $16$
Signature $[4, 6]$
Discriminant $2^{24}\cdot 3^{6}\cdot 13^{8}$
Root discriminant $15.40$
Ramified primes $2, 3, 13$
Class number $1$ (GRH)
Class group Trivial (GRH)
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![1, -4, 0, 10, -22, 42, -67, 82, -93, 82, -67, 42, -22, 10, 0, -4, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^16 - 4*x^15 + 10*x^13 - 22*x^12 + 42*x^11 - 67*x^10 + 82*x^9 - 93*x^8 + 82*x^7 - 67*x^6 + 42*x^5 - 22*x^4 + 10*x^3 - 4*x + 1)
 
gp: K = bnfinit(x^16 - 4*x^15 + 10*x^13 - 22*x^12 + 42*x^11 - 67*x^10 + 82*x^9 - 93*x^8 + 82*x^7 - 67*x^6 + 42*x^5 - 22*x^4 + 10*x^3 - 4*x + 1, 1)
 

Normalized defining polynomial

\( x^{16} - 4 x^{15} + 10 x^{13} - 22 x^{12} + 42 x^{11} - 67 x^{10} + 82 x^{9} - 93 x^{8} + 82 x^{7} - 67 x^{6} + 42 x^{5} - 22 x^{4} + 10 x^{3} - 4 x + 1 \)

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:  \(9976868377454444544=2^{24}\cdot 3^{6}\cdot 13^{8}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $15.40$
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:  $2, 3, 13$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $\frac{1}{3} a^{10} - \frac{1}{3} a^{9} - \frac{1}{3} a^{8} + \frac{1}{3} a^{6} + \frac{1}{3} a^{4} - \frac{1}{3} a^{2} - \frac{1}{3} a + \frac{1}{3}$, $\frac{1}{3} a^{11} + \frac{1}{3} a^{9} - \frac{1}{3} a^{8} + \frac{1}{3} a^{7} + \frac{1}{3} a^{6} + \frac{1}{3} a^{5} + \frac{1}{3} a^{4} - \frac{1}{3} a^{3} + \frac{1}{3} a^{2} + \frac{1}{3}$, $\frac{1}{21} a^{12} - \frac{1}{7} a^{11} - \frac{2}{21} a^{10} - \frac{1}{21} a^{9} - \frac{8}{21} a^{8} - \frac{8}{21} a^{7} - \frac{5}{21} a^{6} - \frac{8}{21} a^{5} - \frac{1}{21} a^{4} - \frac{8}{21} a^{3} - \frac{3}{7} a^{2} + \frac{4}{21} a - \frac{2}{7}$, $\frac{1}{21} a^{13} + \frac{1}{7} a^{11} - \frac{4}{21} a^{9} + \frac{10}{21} a^{8} + \frac{2}{7} a^{7} - \frac{2}{21} a^{6} + \frac{10}{21} a^{5} + \frac{10}{21} a^{4} - \frac{5}{21} a^{3} + \frac{5}{21} a^{2} - \frac{1}{21} a + \frac{1}{7}$, $\frac{1}{357} a^{14} + \frac{5}{357} a^{13} - \frac{1}{51} a^{12} + \frac{10}{357} a^{11} + \frac{58}{357} a^{10} + \frac{16}{51} a^{9} - \frac{6}{119} a^{8} - \frac{158}{357} a^{7} - \frac{23}{119} a^{6} - \frac{6}{17} a^{5} + \frac{41}{357} a^{4} + \frac{95}{357} a^{3} + \frac{163}{357} a^{2} - \frac{3}{17} a + \frac{103}{357}$, $\frac{1}{8211} a^{15} - \frac{5}{8211} a^{14} + \frac{4}{1173} a^{13} + \frac{97}{8211} a^{12} - \frac{671}{8211} a^{11} - \frac{9}{119} a^{10} - \frac{67}{8211} a^{9} + \frac{3116}{8211} a^{8} - \frac{3232}{8211} a^{7} + \frac{71}{8211} a^{6} + \frac{43}{119} a^{5} + \frac{397}{1173} a^{4} + \frac{1270}{8211} a^{3} - \frac{203}{1173} a^{2} + \frac{478}{8211} a - \frac{758}{8211}$

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:  \( 1479.07441648 \) (assuming GRH)
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

\(\Q(\sqrt{26}) \), \(\Q(\sqrt{13}) \), \(\Q(\sqrt{2}) \), 4.2.507.1, 4.2.32448.2, \(\Q(\sqrt{2}, \sqrt{13})\), 8.4.1052872704.3

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 R R ${\href{/LocalNumberField/5.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/7.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/11.8.0.1}{8} }^{2}$ R ${\href{/LocalNumberField/17.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/17.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/19.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/23.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/23.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/29.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/31.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/37.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/41.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/43.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/47.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/53.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/59.8.0.1}{8} }^{2}$

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
2Data not computed
$3$3.4.2.2$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}$
3.8.4.1$x^{8} + 36 x^{4} - 27 x^{2} + 324$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$
$13$13.8.4.1$x^{8} + 26 x^{6} + 845 x^{4} + 6591 x^{2} + 114244$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$
13.8.4.1$x^{8} + 26 x^{6} + 845 x^{4} + 6591 x^{2} + 114244$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$