Properties

Label 18.0.38703284448...4448.1
Degree $18$
Signature $[0, 9]$
Discriminant $-\,2^{18}\cdot 13^{15}\cdot 19^{16}$
Root discriminant $232.27$
Ramified primes $2, 13, 19$
Class number $24559038$ (GRH)
Class group $[3, 9, 909594]$ (GRH)
Galois group $C_{18}$ (as 18T1)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![107653, 0, 11193715, 0, 175757803, 0, 451182511, 0, 146193112, 0, 15825836, 0, 773383, 0, 18798, 0, 221, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 + 221*x^16 + 18798*x^14 + 773383*x^12 + 15825836*x^10 + 146193112*x^8 + 451182511*x^6 + 175757803*x^4 + 11193715*x^2 + 107653)
 
gp: K = bnfinit(x^18 + 221*x^16 + 18798*x^14 + 773383*x^12 + 15825836*x^10 + 146193112*x^8 + 451182511*x^6 + 175757803*x^4 + 11193715*x^2 + 107653, 1)
 

Normalized defining polynomial

\( x^{18} + 221 x^{16} + 18798 x^{14} + 773383 x^{12} + 15825836 x^{10} + 146193112 x^{8} + 451182511 x^{6} + 175757803 x^{4} + 11193715 x^{2} + 107653 \)

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

Invariants

Degree:  $18$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[0, 9]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(-3870328444867146736146206444709275111784448=-\,2^{18}\cdot 13^{15}\cdot 19^{16}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $232.27$
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:  $2, 13, 19$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(988=2^{2}\cdot 13\cdot 19\)
Dirichlet character group:    $\lbrace$$\chi_{988}(1,·)$, $\chi_{988}(199,·)$, $\chi_{988}(9,·)$, $\chi_{988}(311,·)$, $\chi_{988}(81,·)$, $\chi_{988}(467,·)$, $\chi_{988}(251,·)$, $\chi_{988}(729,·)$, $\chi_{988}(283,·)$, $\chi_{988}(803,·)$, $\chi_{988}(549,·)$, $\chi_{988}(491,·)$, $\chi_{988}(885,·)$, $\chi_{988}(823,·)$, $\chi_{988}(633,·)$, $\chi_{988}(571,·)$, $\chi_{988}(61,·)$, $\chi_{988}(757,·)$$\rbrace$
This is a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $\frac{1}{7} a^{5} + \frac{1}{7} a^{3} + \frac{1}{7} a$, $\frac{1}{91} a^{6} - \frac{1}{7} a^{4} - \frac{1}{7} a^{2}$, $\frac{1}{91} a^{7} + \frac{1}{7} a$, $\frac{1}{91} a^{8} + \frac{1}{7} a^{2}$, $\frac{1}{91} a^{9} + \frac{1}{7} a^{3}$, $\frac{1}{7007} a^{10} - \frac{3}{637} a^{8} - \frac{1}{637} a^{6} + \frac{3}{49} a^{4} + \frac{19}{49} a^{2} + \frac{1}{11}$, $\frac{1}{7007} a^{11} - \frac{3}{637} a^{9} - \frac{1}{637} a^{7} + \frac{3}{49} a^{5} + \frac{19}{49} a^{3} + \frac{1}{11} a$, $\frac{1}{637637} a^{12} + \frac{2}{49049} a^{10} + \frac{3}{4459} a^{8} + \frac{20}{4459} a^{6} - \frac{23}{49} a^{4} + \frac{360}{3773} a^{2} - \frac{31}{77}$, $\frac{1}{637637} a^{13} + \frac{2}{49049} a^{11} + \frac{3}{4459} a^{9} + \frac{20}{4459} a^{7} - \frac{2}{49} a^{5} - \frac{1796}{3773} a^{3} + \frac{2}{77} a$, $\frac{1}{49098049} a^{14} - \frac{4}{49098049} a^{12} + \frac{29}{3776773} a^{10} + \frac{232}{49049} a^{8} + \frac{1024}{343343} a^{6} - \frac{69171}{290521} a^{4} + \frac{12321}{290521} a^{2} - \frac{2864}{5929}$, $\frac{1}{49098049} a^{15} - \frac{4}{49098049} a^{13} + \frac{29}{3776773} a^{11} + \frac{232}{49049} a^{9} + \frac{1024}{343343} a^{7} + \frac{13835}{290521} a^{5} + \frac{95327}{290521} a^{3} - \frac{1170}{5929} a$, $\frac{1}{456292767479549} a^{16} + \frac{2616564}{456292767479549} a^{14} - \frac{1348807}{41481160679959} a^{12} - \frac{1518385432}{35099443652273} a^{10} - \frac{12262518952}{3190858513843} a^{8} + \frac{15116022357}{5014206236039} a^{6} - \frac{234306125519}{2699957204021} a^{4} - \frac{37541932345}{245450654911} a^{2} - \frac{3844424433}{55101167429}$, $\frac{1}{456292767479549} a^{17} + \frac{2616564}{456292767479549} a^{15} - \frac{1348807}{41481160679959} a^{13} - \frac{1518385432}{35099443652273} a^{11} - \frac{12262518952}{3190858513843} a^{9} + \frac{15116022357}{5014206236039} a^{7} + \frac{151402046484}{2699957204021} a^{5} - \frac{2477553072}{245450654911} a^{3} + \frac{4027170914}{55101167429} a$

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

Class group and class number

$C_{3}\times C_{9}\times C_{909594}$, which has order $24559038$ (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:  \( 107879432.94074221 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_{18}$ (as 18T1):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A cyclic group of order 18
The 18 conjugacy class representatives for $C_{18}$
Character table for $C_{18}$

Intermediate fields

\(\Q(\sqrt{-13}) \), 3.3.361.1, 6.0.18324175168.4, 9.9.81976414938366169.1

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 $18$ $18$ ${\href{/LocalNumberField/7.1.0.1}{1} }^{18}$ ${\href{/LocalNumberField/11.1.0.1}{1} }^{18}$ R ${\href{/LocalNumberField/17.9.0.1}{9} }^{2}$ R $18$ ${\href{/LocalNumberField/29.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/31.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/37.6.0.1}{6} }^{3}$ $18$ $18$ ${\href{/LocalNumberField/47.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/53.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/59.9.0.1}{9} }^{2}$

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
13Data not computed
$19$19.9.8.3$x^{9} - 77824$$9$$1$$8$$C_9$$[\ ]_{9}$
19.9.8.3$x^{9} - 77824$$9$$1$$8$$C_9$$[\ ]_{9}$