Properties

Label 16.8.17983880206...3984.1
Degree $16$
Signature $[8, 4]$
Discriminant $2^{30}\cdot 7^{4}\cdot 17^{8}$
Root discriminant $24.60$
Ramified primes $2, 7, 17$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group $C_2^2.C_2^5.C_2$ (as 16T511)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![4, 40, 42, 80, -277, -452, 580, 852, -956, -568, 910, -112, -224, 84, 8, -8, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^16 - 8*x^15 + 8*x^14 + 84*x^13 - 224*x^12 - 112*x^11 + 910*x^10 - 568*x^9 - 956*x^8 + 852*x^7 + 580*x^6 - 452*x^5 - 277*x^4 + 80*x^3 + 42*x^2 + 40*x + 4)
 
gp: K = bnfinit(x^16 - 8*x^15 + 8*x^14 + 84*x^13 - 224*x^12 - 112*x^11 + 910*x^10 - 568*x^9 - 956*x^8 + 852*x^7 + 580*x^6 - 452*x^5 - 277*x^4 + 80*x^3 + 42*x^2 + 40*x + 4, 1)
 

Normalized defining polynomial

\( x^{16} - 8 x^{15} + 8 x^{14} + 84 x^{13} - 224 x^{12} - 112 x^{11} + 910 x^{10} - 568 x^{9} - 956 x^{8} + 852 x^{7} + 580 x^{6} - 452 x^{5} - 277 x^{4} + 80 x^{3} + 42 x^{2} + 40 x + 4 \)

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

Invariants

Degree:  $16$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[8, 4]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(17983880206872670633984=2^{30}\cdot 7^{4}\cdot 17^{8}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $24.60$
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:  $2, 7, 17$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $\frac{1}{14} a^{12} - \frac{3}{7} a^{11} + \frac{3}{14} a^{10} - \frac{1}{7} a^{9} + \frac{3}{14} a^{8} + \frac{2}{7} a^{7} - \frac{1}{14} a^{6} + \frac{3}{7} a^{5} - \frac{1}{2} a^{4} - \frac{2}{7} a^{3} + \frac{5}{14} a^{2} - \frac{1}{7} a - \frac{2}{7}$, $\frac{1}{14} a^{13} - \frac{5}{14} a^{11} + \frac{1}{7} a^{10} + \frac{5}{14} a^{9} - \frac{3}{7} a^{8} - \frac{5}{14} a^{7} + \frac{1}{14} a^{5} - \frac{2}{7} a^{4} - \frac{5}{14} a^{3} - \frac{1}{7} a + \frac{2}{7}$, $\frac{1}{155974} a^{14} - \frac{1}{22282} a^{13} + \frac{5199}{155974} a^{12} - \frac{31103}{155974} a^{11} + \frac{10917}{22282} a^{10} + \frac{58823}{155974} a^{9} + \frac{64481}{155974} a^{8} - \frac{16865}{155974} a^{7} + \frac{835}{11998} a^{6} - \frac{5677}{22282} a^{5} + \frac{11671}{155974} a^{4} + \frac{46601}{155974} a^{3} + \frac{19148}{77987} a^{2} - \frac{34329}{77987} a - \frac{3275}{77987}$, $\frac{1}{198554902} a^{15} + \frac{629}{198554902} a^{14} - \frac{3414343}{99277451} a^{13} - \frac{985975}{99277451} a^{12} - \frac{26246526}{99277451} a^{11} - \frac{1602906}{5225129} a^{10} - \frac{46041390}{99277451} a^{9} + \frac{33893578}{99277451} a^{8} - \frac{5953686}{99277451} a^{7} + \frac{6601635}{99277451} a^{6} - \frac{1192823}{5225129} a^{5} + \frac{25933121}{99277451} a^{4} + \frac{76390745}{198554902} a^{3} - \frac{60751655}{198554902} a^{2} - \frac{46725513}{99277451} a + \frac{2395782}{99277451}$

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:  $11$
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:  \( 263219.156169 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_2^2.C_2^5.C_2$ (as 16T511):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 256
The 46 conjugacy class representatives for $C_2^2.C_2^5.C_2$
Character table for $C_2^2.C_2^5.C_2$ is not computed

Intermediate fields

\(\Q(\sqrt{17}) \), 4.4.9248.1, 4.2.1156.1, 4.2.2312.1, 8.4.134103990272.3, 8.8.134103990272.2, 8.4.85525504.1

Fields in the database are given up to isomorphism. Isomorphic intermediate fields are shown with their multiplicities.

Sibling fields

Degree 16 siblings: data not computed
Degree 32 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 ${\href{/LocalNumberField/3.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/5.8.0.1}{8} }^{2}$ R ${\href{/LocalNumberField/11.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/13.4.0.1}{4} }^{2}{,}\,{\href{/LocalNumberField/13.2.0.1}{2} }^{4}$ R ${\href{/LocalNumberField/19.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/23.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/29.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/31.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/37.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/41.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/43.4.0.1}{4} }^{2}{,}\,{\href{/LocalNumberField/43.1.0.1}{1} }^{8}$ ${\href{/LocalNumberField/47.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/53.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/53.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/59.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/59.1.0.1}{1} }^{4}$

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
$2$2.4.6.2$x^{4} - 2 x^{2} + 4$$2$$2$$6$$C_2^2$$[3]^{2}$
2.4.6.2$x^{4} - 2 x^{2} + 4$$2$$2$$6$$C_2^2$$[3]^{2}$
2.8.18.1$x^{8} + 14 x^{6} + 10 x^{4} + 12 x^{2} + 16 x + 4$$4$$2$$18$$D_4\times C_2$$[2, 3, 7/2]^{2}$
$7$7.4.0.1$x^{4} + x^{2} - 3 x + 5$$1$$4$$0$$C_4$$[\ ]^{4}$
7.4.0.1$x^{4} + x^{2} - 3 x + 5$$1$$4$$0$$C_4$$[\ ]^{4}$
7.8.4.1$x^{8} + 14 x^{6} + 539 x^{4} + 343 x^{2} + 60025$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$
$17$17.4.2.1$x^{4} + 85 x^{2} + 2601$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
17.4.2.1$x^{4} + 85 x^{2} + 2601$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
17.4.2.1$x^{4} + 85 x^{2} + 2601$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
17.4.2.1$x^{4} + 85 x^{2} + 2601$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$