Properties

Label 18.0.60063993430...8107.1
Degree $18$
Signature $[0, 9]$
Discriminant $-\,3^{27}\cdot 31^{12}$
Root discriminant $51.28$
Ramified primes $3, 31$
Class number $91$ (GRH)
Class group $[91]$ (GRH)
Galois group $C_6 \times C_3$ (as 18T2)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![262144, 0, 0, -536576, 0, 0, 1101888, 0, 0, 6312, 0, 0, 1097, 0, 0, -7, 0, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 7*x^15 + 1097*x^12 + 6312*x^9 + 1101888*x^6 - 536576*x^3 + 262144)
 
gp: K = bnfinit(x^18 - 7*x^15 + 1097*x^12 + 6312*x^9 + 1101888*x^6 - 536576*x^3 + 262144, 1)
 

Normalized defining polynomial

\( x^{18} - 7 x^{15} + 1097 x^{12} + 6312 x^{9} + 1101888 x^{6} - 536576 x^{3} + 262144 \)

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:  \(-6006399343075824213089699938107=-\,3^{27}\cdot 31^{12}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $51.28$
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:  $3, 31$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(279=3^{2}\cdot 31\)
Dirichlet character group:    $\lbrace$$\chi_{279}(1,·)$, $\chi_{279}(67,·)$, $\chi_{279}(5,·)$, $\chi_{279}(32,·)$, $\chi_{279}(211,·)$, $\chi_{279}(149,·)$, $\chi_{279}(25,·)$, $\chi_{279}(218,·)$, $\chi_{279}(94,·)$, $\chi_{279}(160,·)$, $\chi_{279}(98,·)$, $\chi_{279}(125,·)$, $\chi_{279}(242,·)$, $\chi_{279}(118,·)$, $\chi_{279}(56,·)$, $\chi_{279}(187,·)$, $\chi_{279}(253,·)$, $\chi_{279}(191,·)$$\rbrace$
This is a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $\frac{1}{2} a^{7} - \frac{1}{2} a^{4} - \frac{1}{2} a$, $\frac{1}{4} a^{8} + \frac{1}{4} a^{5} + \frac{1}{4} a^{2}$, $\frac{1}{8} a^{9} + \frac{1}{8} a^{6} + \frac{1}{8} a^{3}$, $\frac{1}{16} a^{10} + \frac{1}{16} a^{7} + \frac{1}{16} a^{4}$, $\frac{1}{32} a^{11} + \frac{1}{32} a^{8} - \frac{15}{32} a^{5} - \frac{1}{2} a^{2}$, $\frac{1}{17728} a^{12} + \frac{993}{17728} a^{9} - \frac{5903}{17728} a^{6} + \frac{325}{1108} a^{3} - \frac{122}{277}$, $\frac{1}{70912} a^{13} - \frac{1223}{70912} a^{10} + \frac{9609}{70912} a^{7} + \frac{2589}{8864} a^{4} - \frac{399}{1108} a$, $\frac{1}{283648} a^{14} - \frac{1223}{283648} a^{11} + \frac{9609}{283648} a^{8} + \frac{11453}{35456} a^{5} + \frac{1817}{4432} a^{2}$, $\frac{1}{21362507763712} a^{15} - \frac{107590791}{21362507763712} a^{12} + \frac{363905363913}{21362507763712} a^{9} + \frac{1205926914949}{2670313470464} a^{6} - \frac{34819017823}{333789183808} a^{3} + \frac{471858849}{5215455997}$, $\frac{1}{85450031054848} a^{16} - \frac{107590791}{85450031054848} a^{13} + \frac{363905363913}{85450031054848} a^{10} + \frac{1205926914949}{10681253881856} a^{7} - \frac{368608201631}{1335156735232} a^{4} - \frac{9959053145}{20861823988} a$, $\frac{1}{341800124219392} a^{17} - \frac{107590791}{341800124219392} a^{14} - \frac{4976721577015}{341800124219392} a^{11} + \frac{538348547333}{42725015527424} a^{8} + \frac{2218257972881}{5340626940928} a^{5} + \frac{10902770843}{83447295952} a^{2}$

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

Class group and class number

$C_{91}$, which has order $91$ (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:  \( \frac{1023218599}{341800124219392} a^{17} - \frac{6692027985}{341800124219392} a^{14} + \frac{1118971551711}{341800124219392} a^{11} + \frac{875867309915}{42725015527424} a^{8} + \frac{17658575413967}{5340626940928} a^{5} + \frac{54675803}{10430911994} a^{2} \) (order $18$)
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:  \( 4617140.62551 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_3\times C_6$ (as 18T2):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
An abelian group of order 18
The 18 conjugacy class representatives for $C_6 \times C_3$
Character table for $C_6 \times C_3$

Intermediate fields

\(\Q(\sqrt{-3}) \), 3.3.77841.1, 3.3.77841.2, \(\Q(\zeta_{9})^+\), 3.3.961.1, 6.0.18177663843.2, 6.0.18177663843.1, \(\Q(\zeta_{9})\), 6.0.24935067.1, 9.9.471655843734321.1

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 ${\href{/LocalNumberField/2.6.0.1}{6} }^{3}$ R ${\href{/LocalNumberField/5.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/7.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/11.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/13.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/17.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/19.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/23.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/29.6.0.1}{6} }^{3}$ R ${\href{/LocalNumberField/37.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/41.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/43.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/47.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/53.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/59.6.0.1}{6} }^{3}$

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
3Data not computed
$31$31.9.6.1$x^{9} + 837 x^{6} + 232562 x^{3} + 21717639$$3$$3$$6$$C_3^2$$[\ ]_{3}^{3}$
31.9.6.1$x^{9} + 837 x^{6} + 232562 x^{3} + 21717639$$3$$3$$6$$C_3^2$$[\ ]_{3}^{3}$