Properties

Label 16.8.21431487973...0000.1
Degree $16$
Signature $[8, 4]$
Discriminant $2^{8}\cdot 5^{12}\cdot 7^{8}\cdot 29^{6}$
Root discriminant $44.23$
Ramified primes $2, 5, 7, 29$
Class number $2$ (GRH)
Class group $[2]$ (GRH)
Galois group $(C_2^2\times C_4).C_2^4$ (as 16T471)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![931, 588, -4417, -1134, 3712, 3633, -892, -2112, -235, -222, 431, 81, 7, -39, -2, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^16 - 2*x^14 - 39*x^13 + 7*x^12 + 81*x^11 + 431*x^10 - 222*x^9 - 235*x^8 - 2112*x^7 - 892*x^6 + 3633*x^5 + 3712*x^4 - 1134*x^3 - 4417*x^2 + 588*x + 931)
 
gp: K = bnfinit(x^16 - 2*x^14 - 39*x^13 + 7*x^12 + 81*x^11 + 431*x^10 - 222*x^9 - 235*x^8 - 2112*x^7 - 892*x^6 + 3633*x^5 + 3712*x^4 - 1134*x^3 - 4417*x^2 + 588*x + 931, 1)
 

Normalized defining polynomial

\( x^{16} - 2 x^{14} - 39 x^{13} + 7 x^{12} + 81 x^{11} + 431 x^{10} - 222 x^{9} - 235 x^{8} - 2112 x^{7} - 892 x^{6} + 3633 x^{5} + 3712 x^{4} - 1134 x^{3} - 4417 x^{2} + 588 x + 931 \)

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:  \(214314879732757562500000000=2^{8}\cdot 5^{12}\cdot 7^{8}\cdot 29^{6}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $44.23$
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:  $2, 5, 7, 29$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $\frac{1}{91} a^{14} - \frac{1}{13} a^{13} - \frac{9}{91} a^{12} - \frac{3}{7} a^{11} - \frac{5}{13} a^{10} - \frac{38}{91} a^{9} + \frac{18}{91} a^{8} - \frac{40}{91} a^{7} + \frac{38}{91} a^{6} + \frac{44}{91} a^{5} + \frac{3}{7} a^{4} - \frac{2}{13} a^{3} - \frac{12}{91} a^{2} + \frac{1}{13} a + \frac{4}{13}$, $\frac{1}{5339231602282697798015701} a^{15} - \frac{20276408449972284384459}{5339231602282697798015701} a^{14} - \frac{1643002587912039128047723}{5339231602282697798015701} a^{13} - \frac{2075725972947838303083571}{5339231602282697798015701} a^{12} + \frac{1029797064586306596063683}{5339231602282697798015701} a^{11} + \frac{2357819271859733134846425}{5339231602282697798015701} a^{10} - \frac{1957454838801946434458479}{5339231602282697798015701} a^{9} + \frac{464906303419013054426960}{5339231602282697798015701} a^{8} + \frac{2415800664813212523822834}{5339231602282697798015701} a^{7} + \frac{985139900900450367157300}{5339231602282697798015701} a^{6} + \frac{339199345342817599360503}{5339231602282697798015701} a^{5} + \frac{2071310035622582018169021}{5339231602282697798015701} a^{4} + \frac{96490022103871815989495}{5339231602282697798015701} a^{3} + \frac{755529628906788515289736}{5339231602282697798015701} a^{2} + \frac{365804066244778188206246}{762747371754671114002243} a + \frac{258883264320718274268946}{762747371754671114002243}$

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

Class group and class number

$C_{2}$, which has order $2$ (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:  \( 6581032.58801 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$(C_2^2\times C_4).C_2^4$ (as 16T471):

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 $(C_2^2\times C_4).C_2^4$
Character table for $(C_2^2\times C_4).C_2^4$ is not computed

Intermediate fields

\(\Q(\sqrt{5}) \), 4.4.725.1, 4.4.6125.1, 4.4.177625.1, 8.8.31550640625.1

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 ${\href{/LocalNumberField/3.8.0.1}{8} }^{2}$ R R ${\href{/LocalNumberField/11.4.0.1}{4} }^{2}{,}\,{\href{/LocalNumberField/11.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/13.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/17.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/19.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/19.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/23.4.0.1}{4} }^{4}$ R ${\href{/LocalNumberField/31.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/37.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/41.4.0.1}{4} }^{2}{,}\,{\href{/LocalNumberField/41.2.0.1}{2} }^{4}$ ${\href{/LocalNumberField/43.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/47.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/53.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/59.4.0.1}{4} }^{4}$

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
$2$2.8.8.4$x^{8} + 2 x^{7} + 2 x^{6} + 8 x^{3} + 48$$2$$4$$8$$C_8$$[2]^{4}$
2.8.0.1$x^{8} + x^{4} + x^{3} + x + 1$$1$$8$$0$$C_8$$[\ ]^{8}$
$5$5.8.6.1$x^{8} - 5 x^{4} + 400$$4$$2$$6$$C_4\times C_2$$[\ ]_{4}^{2}$
5.8.6.1$x^{8} - 5 x^{4} + 400$$4$$2$$6$$C_4\times C_2$$[\ ]_{4}^{2}$
$7$7.4.2.2$x^{4} - 7 x^{2} + 147$$2$$2$$2$$C_4$$[\ ]_{2}^{2}$
7.4.2.2$x^{4} - 7 x^{2} + 147$$2$$2$$2$$C_4$$[\ ]_{2}^{2}$
7.8.4.1$x^{8} + 14 x^{6} + 539 x^{4} + 343 x^{2} + 60025$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$
$29$29.4.2.2$x^{4} - 29 x^{2} + 2523$$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}$