Properties

Label 16.2.27187276612...2087.1
Degree $16$
Signature $[2, 7]$
Discriminant $-\,23^{7}\cdot 41^{8}$
Root discriminant $25.24$
Ramified primes $23, 41$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group $D_{16}$ (as 16T56)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, 38, -55, -32, 66, 46, -59, -28, 58, -2, -38, 11, 0, -1, 8, -5, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^16 - 5*x^15 + 8*x^14 - x^13 + 11*x^11 - 38*x^10 - 2*x^9 + 58*x^8 - 28*x^7 - 59*x^6 + 46*x^5 + 66*x^4 - 32*x^3 - 55*x^2 + 38*x + 1)
 
gp: K = bnfinit(x^16 - 5*x^15 + 8*x^14 - x^13 + 11*x^11 - 38*x^10 - 2*x^9 + 58*x^8 - 28*x^7 - 59*x^6 + 46*x^5 + 66*x^4 - 32*x^3 - 55*x^2 + 38*x + 1, 1)
 

Normalized defining polynomial

\( x^{16} - 5 x^{15} + 8 x^{14} - x^{13} + 11 x^{11} - 38 x^{10} - 2 x^{9} + 58 x^{8} - 28 x^{7} - 59 x^{6} + 46 x^{5} + 66 x^{4} - 32 x^{3} - 55 x^{2} + 38 x + 1 \)

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

Invariants

Degree:  $16$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[2, 7]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(-27187276612503486242087=-\,23^{7}\cdot 41^{8}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $25.24$
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:  $23, 41$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $\frac{1}{3} a^{8} - \frac{1}{3}$, $\frac{1}{3} a^{9} - \frac{1}{3} a$, $\frac{1}{3} a^{10} - \frac{1}{3} a^{2}$, $\frac{1}{3} a^{11} - \frac{1}{3} a^{3}$, $\frac{1}{3} a^{12} - \frac{1}{3} a^{4}$, $\frac{1}{15} a^{13} - \frac{2}{15} a^{12} - \frac{1}{15} a^{11} + \frac{1}{15} a^{10} - \frac{2}{15} a^{9} - \frac{2}{15} a^{8} + \frac{2}{5} a^{7} - \frac{2}{5} a^{6} - \frac{1}{15} a^{5} - \frac{4}{15} a^{4} - \frac{2}{15} a^{3} - \frac{7}{15} a^{2} + \frac{1}{3} a - \frac{4}{15}$, $\frac{1}{135} a^{14} + \frac{2}{135} a^{13} + \frac{11}{135} a^{12} - \frac{2}{15} a^{11} - \frac{13}{135} a^{10} + \frac{2}{27} a^{9} + \frac{13}{135} a^{8} - \frac{4}{45} a^{7} + \frac{13}{27} a^{6} - \frac{8}{135} a^{5} + \frac{7}{135} a^{4} - \frac{1}{9} a^{3} - \frac{53}{135} a^{2} - \frac{49}{135} a - \frac{31}{135}$, $\frac{1}{715809015} a^{15} - \frac{174145}{143161803} a^{14} - \frac{48349}{47720601} a^{13} - \frac{52512146}{715809015} a^{12} - \frac{13012028}{143161803} a^{11} - \frac{55787491}{715809015} a^{10} - \frac{10982912}{79534335} a^{9} + \frac{95557436}{715809015} a^{8} + \frac{18730877}{715809015} a^{7} - \frac{102113836}{715809015} a^{6} - \frac{14706403}{47720601} a^{5} + \frac{230126654}{715809015} a^{4} + \frac{7169236}{715809015} a^{3} - \frac{319863014}{715809015} a^{2} - \frac{6969206}{238603005} a - \frac{52307014}{143161803}$

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:  $8$
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:  \( 151970.25308 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$D_{16}$ (as 16T56):

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 $D_{16}$
Character table for $D_{16}$

Intermediate fields

\(\Q(\sqrt{41}) \), 4.2.38663.1, 8.2.34381034087.1

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 ${\href{/LocalNumberField/2.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/3.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/5.2.0.1}{2} }^{7}{,}\,{\href{/LocalNumberField/5.1.0.1}{1} }^{2}$ $16$ $16$ ${\href{/LocalNumberField/13.2.0.1}{2} }^{8}$ $16$ $16$ R ${\href{/LocalNumberField/29.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/31.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/37.2.0.1}{2} }^{7}{,}\,{\href{/LocalNumberField/37.1.0.1}{1} }^{2}$ R ${\href{/LocalNumberField/43.2.0.1}{2} }^{7}{,}\,{\href{/LocalNumberField/43.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/47.2.0.1}{2} }^{8}$ $16$ ${\href{/LocalNumberField/59.4.0.1}{4} }^{4}$

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
$23$23.2.0.1$x^{2} - x + 7$$1$$2$$0$$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$$[\ ]_{2}^{2}$
$41$41.4.2.1$x^{4} + 943 x^{2} + 242064$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
41.4.2.1$x^{4} + 943 x^{2} + 242064$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
41.4.2.1$x^{4} + 943 x^{2} + 242064$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
41.4.2.1$x^{4} + 943 x^{2} + 242064$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$