Properties

Label 16.0.39615410820...0000.1
Degree $16$
Signature $[0, 8]$
Discriminant $2^{44}\cdot 5^{8}\cdot 7^{8}$
Root discriminant $39.80$
Ramified primes $2, 5, 7$
Class number $128$ (GRH)
Class group $[2, 8, 8]$ (GRH)
Galois group $C_4\times C_2^2$ (as 16T2)

Related objects

Downloads

Learn more about

Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![55036, -47168, 73496, -61552, 55602, -37312, 25876, -13520, 6291, -2520, 988, -160, -34, 0, 20, -8, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^16 - 8*x^15 + 20*x^14 - 34*x^12 - 160*x^11 + 988*x^10 - 2520*x^9 + 6291*x^8 - 13520*x^7 + 25876*x^6 - 37312*x^5 + 55602*x^4 - 61552*x^3 + 73496*x^2 - 47168*x + 55036)
 
gp: K = bnfinit(x^16 - 8*x^15 + 20*x^14 - 34*x^12 - 160*x^11 + 988*x^10 - 2520*x^9 + 6291*x^8 - 13520*x^7 + 25876*x^6 - 37312*x^5 + 55602*x^4 - 61552*x^3 + 73496*x^2 - 47168*x + 55036, 1)
 

Normalized defining polynomial

\( x^{16} - 8 x^{15} + 20 x^{14} - 34 x^{12} - 160 x^{11} + 988 x^{10} - 2520 x^{9} + 6291 x^{8} - 13520 x^{7} + 25876 x^{6} - 37312 x^{5} + 55602 x^{4} - 61552 x^{3} + 73496 x^{2} - 47168 x + 55036 \)

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:  \(39615410820716953600000000=2^{44}\cdot 5^{8}\cdot 7^{8}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $39.80$
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:  $2, 5, 7$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(560=2^{4}\cdot 5\cdot 7\)
Dirichlet character group:    $\lbrace$$\chi_{560}(1,·)$, $\chi_{560}(69,·)$, $\chi_{560}(321,·)$, $\chi_{560}(141,·)$, $\chi_{560}(461,·)$, $\chi_{560}(209,·)$, $\chi_{560}(281,·)$, $\chi_{560}(169,·)$, $\chi_{560}(349,·)$, $\chi_{560}(421,·)$, $\chi_{560}(489,·)$, $\chi_{560}(29,·)$, $\chi_{560}(449,·)$, $\chi_{560}(181,·)$, $\chi_{560}(41,·)$, $\chi_{560}(309,·)$$\rbrace$
This is a CM field.

Integral basis (with respect to field generator \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $\frac{1}{2} a^{8} - \frac{1}{2} a^{4}$, $\frac{1}{2} a^{9} - \frac{1}{2} a^{5}$, $\frac{1}{2} a^{10} - \frac{1}{2} a^{6}$, $\frac{1}{2} a^{11} - \frac{1}{2} a^{7}$, $\frac{1}{2} a^{12} - \frac{1}{2} a^{4}$, $\frac{1}{2} a^{13} - \frac{1}{2} a^{5}$, $\frac{1}{15213630121762} a^{14} - \frac{7}{15213630121762} a^{13} + \frac{399050155412}{7606815060881} a^{12} + \frac{1409106598014}{7606815060881} a^{11} + \frac{3454518763187}{15213630121762} a^{10} + \frac{3802478095741}{15213630121762} a^{9} + \frac{777420658819}{15213630121762} a^{8} + \frac{2537896973436}{7606815060881} a^{7} + \frac{2993650546753}{7606815060881} a^{6} - \frac{2177773688846}{7606815060881} a^{5} - \frac{3811350157817}{15213630121762} a^{4} + \frac{403633356699}{7606815060881} a^{3} - \frac{1747672498190}{7606815060881} a^{2} + \frac{1677389937641}{7606815060881} a + \frac{2774098182768}{7606815060881}$, $\frac{1}{823985421024751682} a^{15} + \frac{27073}{823985421024751682} a^{14} - \frac{71336312590881386}{411992710512375841} a^{13} + \frac{124999598122743619}{823985421024751682} a^{12} - \frac{71206649604215864}{411992710512375841} a^{11} + \frac{56324417677248087}{823985421024751682} a^{10} + \frac{40459078083005041}{823985421024751682} a^{9} - \frac{81520273861214893}{823985421024751682} a^{8} + \frac{392172689695987551}{823985421024751682} a^{7} + \frac{134914522848358993}{411992710512375841} a^{6} + \frac{32769399278238957}{823985421024751682} a^{5} - \frac{183438989323614092}{411992710512375841} a^{4} + \frac{40732145035442488}{411992710512375841} a^{3} - \frac{48139223072561826}{411992710512375841} a^{2} - \frac{195542193889087270}{411992710512375841} a - \frac{75165266368468477}{411992710512375841}$

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

Class group and class number

$C_{2}\times C_{8}\times C_{8}$, which has order $128$ (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:  \( 12198.9512748 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_2^2\times C_4$ (as 16T2):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
An abelian group of order 16
The 16 conjugacy class representatives for $C_4\times C_2^2$
Character table for $C_4\times C_2^2$

Intermediate fields

\(\Q(\sqrt{10}) \), \(\Q(\sqrt{-70}) \), \(\Q(\sqrt{-7}) \), \(\Q(\sqrt{2}) \), \(\Q(\sqrt{5}) \), \(\Q(\sqrt{-35}) \), \(\Q(\sqrt{-14}) \), \(\Q(\sqrt{-7}, \sqrt{10})\), \(\Q(\sqrt{2}, \sqrt{5})\), \(\Q(\sqrt{10}, \sqrt{-14})\), \(\Q(\sqrt{2}, \sqrt{-35})\), \(\Q(\sqrt{5}, \sqrt{-14})\), \(\Q(\sqrt{2}, \sqrt{-7})\), \(\Q(\sqrt{5}, \sqrt{-7})\), 4.0.2508800.1, 4.0.100352.5, \(\Q(\zeta_{16})^+\), 4.4.51200.1, 8.0.6146560000.2, 8.0.6294077440000.7, 8.8.2621440000.1, 8.0.6294077440000.6, 8.0.6294077440000.2, 8.0.6294077440000.5, 8.0.10070523904.2

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

Frobenius cycle types

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59
Cycle type R ${\href{/LocalNumberField/3.4.0.1}{4} }^{4}$ R R ${\href{/LocalNumberField/11.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/13.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/17.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/19.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/23.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/29.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/31.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/37.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/41.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/43.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/47.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/53.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/59.4.0.1}{4} }^{4}$

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$2.8.22.2$x^{8} + 10 x^{4} + 16 x + 4$$4$$2$$22$$C_4\times C_2$$[3, 4]^{2}$
2.8.22.2$x^{8} + 10 x^{4} + 16 x + 4$$4$$2$$22$$C_4\times C_2$$[3, 4]^{2}$
$5$5.8.4.1$x^{8} + 10 x^{6} + 125 x^{4} + 2500$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$
5.8.4.1$x^{8} + 10 x^{6} + 125 x^{4} + 2500$$2$$4$$4$$C_4\times C_2$$[\ ]_{2}^{4}$
$7$7.4.2.1$x^{4} + 35 x^{2} + 441$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
7.4.2.1$x^{4} + 35 x^{2} + 441$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
7.4.2.1$x^{4} + 35 x^{2} + 441$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
7.4.2.1$x^{4} + 35 x^{2} + 441$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$