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Properties

Label 16.0.42786095104...0000.2
Degree $16$
Signature $[0, 8]$
Discriminant $2^{36}\cdot 5^{14}\cdot 101^{2}$
Root discriminant $34.63$
Ramified primes $2, 5, 101$
Class number $4$ (GRH)
Class group $[2, 2]$ (GRH)
Galois group $C_2^3.C_2^4.C_2$ (as 16T554)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![625, 0, 2500, 0, 1000, 0, -100, 0, 430, 0, -20, 0, 40, 0, 20, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^16 + 20*x^14 + 40*x^12 - 20*x^10 + 430*x^8 - 100*x^6 + 1000*x^4 + 2500*x^2 + 625)
 
gp: K = bnfinit(x^16 + 20*x^14 + 40*x^12 - 20*x^10 + 430*x^8 - 100*x^6 + 1000*x^4 + 2500*x^2 + 625, 1)
 

Normalized defining polynomial

\( x^{16} + 20 x^{14} + 40 x^{12} - 20 x^{10} + 430 x^{8} - 100 x^{6} + 1000 x^{4} + 2500 x^{2} + 625 \)

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

Invariants

Degree:  $16$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[0, 8]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(4278609510400000000000000=2^{36}\cdot 5^{14}\cdot 101^{2}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $34.63$
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:  $2, 5, 101$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $\frac{1}{2} a^{4} - \frac{1}{2}$, $\frac{1}{2} a^{5} - \frac{1}{2} a$, $\frac{1}{2} a^{6} - \frac{1}{2} a^{2}$, $\frac{1}{2} a^{7} - \frac{1}{2} a^{3}$, $\frac{1}{20} a^{8} - \frac{1}{4}$, $\frac{1}{40} a^{9} - \frac{1}{40} a^{8} - \frac{1}{2} a^{3} - \frac{1}{2} a^{2} + \frac{3}{8} a - \frac{3}{8}$, $\frac{1}{40} a^{10} - \frac{1}{40} a^{8} - \frac{1}{8} a^{2} + \frac{1}{8}$, $\frac{1}{200} a^{11} - \frac{1}{40} a^{8} + \frac{1}{5} a^{7} - \frac{1}{10} a^{5} + \frac{11}{40} a^{3} - \frac{1}{2} a^{2} - \frac{3}{8}$, $\frac{1}{48200} a^{12} - \frac{61}{9640} a^{10} + \frac{7}{964} a^{8} - \frac{491}{2410} a^{6} + \frac{591}{9640} a^{4} + \frac{177}{1928} a^{2} - \frac{359}{964}$, $\frac{1}{96400} a^{13} - \frac{1}{96400} a^{12} - \frac{4}{6025} a^{11} - \frac{9}{964} a^{10} - \frac{171}{19280} a^{9} + \frac{171}{19280} a^{8} - \frac{9}{4820} a^{7} + \frac{491}{4820} a^{6} - \frac{373}{19280} a^{5} + \frac{4229}{19280} a^{4} - \frac{321}{4820} a^{3} + \frac{4}{241} a^{2} + \frac{487}{3856} a - \frac{487}{3856}$, $\frac{1}{482000} a^{14} - \frac{1}{96400} a^{12} - \frac{637}{96400} a^{10} + \frac{961}{96400} a^{8} + \frac{18711}{96400} a^{6} - \frac{1959}{19280} a^{4} + \frac{17}{3856} a^{2} + \frac{59}{3856}$, $\frac{1}{482000} a^{15} - \frac{1}{96400} a^{12} - \frac{219}{96400} a^{11} - \frac{9}{964} a^{10} + \frac{53}{48200} a^{9} - \frac{311}{19280} a^{8} - \frac{10389}{96400} a^{7} + \frac{491}{4820} a^{6} - \frac{213}{964} a^{5} + \frac{4229}{19280} a^{4} - \frac{5537}{19280} a^{3} - \frac{233}{482} a^{2} + \frac{273}{1928} a + \frac{1923}{3856}$

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

Class group and class number

$C_{2}\times C_{2}$, which has order $4$ (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:  $7$
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:  \( 174030.782341 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_2^3.C_2^4.C_2$ (as 16T554):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 256
The 40 conjugacy class representatives for $C_2^3.C_2^4.C_2$
Character table for $C_2^3.C_2^4.C_2$ is not computed

Intermediate fields

\(\Q(\sqrt{5}) \), \(\Q(\zeta_{20})^+\), 8.4.6464000000.2, 8.0.5120000000.1, 8.4.517120000000.4

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 ${\href{/LocalNumberField/7.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/11.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/13.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/17.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/19.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/19.1.0.1}{1} }^{4}$ ${\href{/LocalNumberField/23.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/29.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/31.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/37.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/41.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/43.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/47.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/53.8.0.1}{8} }^{2}$ ${\href{/LocalNumberField/59.2.0.1}{2} }^{4}{,}\,{\href{/LocalNumberField/59.1.0.1}{1} }^{8}$

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
$5$5.8.7.2$x^{8} - 20$$8$$1$$7$$C_8:C_2$$[\ ]_{8}^{2}$
5.8.7.2$x^{8} - 20$$8$$1$$7$$C_8:C_2$$[\ ]_{8}^{2}$
$101$$\Q_{101}$$x + 2$$1$$1$$0$Trivial$[\ ]$
$\Q_{101}$$x + 2$$1$$1$$0$Trivial$[\ ]$
$\Q_{101}$$x + 2$$1$$1$$0$Trivial$[\ ]$
$\Q_{101}$$x + 2$$1$$1$$0$Trivial$[\ ]$
101.2.0.1$x^{2} - x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
101.2.0.1$x^{2} - x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
101.2.0.1$x^{2} - x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
101.2.0.1$x^{2} - x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
101.2.1.1$x^{2} - 101$$2$$1$$1$$C_2$$[\ ]_{2}$
101.2.1.1$x^{2} - 101$$2$$1$$1$$C_2$$[\ ]_{2}$