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Properties

Label 18.2.17897673223...6688.2
Degree $18$
Signature $[2, 8]$
Discriminant $2^{12}\cdot 3^{21}\cdot 11^{15}$
Root discriminant $42.18$
Ramified primes $2, 3, 11$
Class number $18$ (GRH)
Class group $[3, 6]$ (GRH)
Galois group $C_2\times C_3:S_3$ (as 18T12)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![-8, 0, 0, -148, 0, 0, -490, 0, 0, 3983, 0, 0, 245, 0, 0, -37, 0, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 37*x^15 + 245*x^12 + 3983*x^9 - 490*x^6 - 148*x^3 - 8)
 
gp: K = bnfinit(x^18 - 37*x^15 + 245*x^12 + 3983*x^9 - 490*x^6 - 148*x^3 - 8, 1)
 

Normalized defining polynomial

\( x^{18} - 37 x^{15} + 245 x^{12} + 3983 x^{9} - 490 x^{6} - 148 x^{3} - 8 \)

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

Invariants

Degree:  $18$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[2, 8]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(178976732236484163896033906688=2^{12}\cdot 3^{21}\cdot 11^{15}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $42.18$
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:  $2, 3, 11$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $\frac{1}{9} a^{6} + \frac{2}{9}$, $\frac{1}{9} a^{7} + \frac{2}{9} a$, $\frac{1}{9} a^{8} + \frac{2}{9} a^{2}$, $\frac{1}{9} a^{9} + \frac{2}{9} a^{3}$, $\frac{1}{9} a^{10} + \frac{2}{9} a^{4}$, $\frac{1}{27} a^{11} + \frac{1}{27} a^{10} + \frac{1}{27} a^{9} + \frac{1}{27} a^{8} + \frac{1}{27} a^{7} + \frac{1}{27} a^{6} + \frac{2}{27} a^{5} + \frac{2}{27} a^{4} + \frac{2}{27} a^{3} + \frac{2}{27} a^{2} + \frac{2}{27} a + \frac{2}{27}$, $\frac{1}{810} a^{12} + \frac{1}{90} a^{9} + \frac{31}{810} a^{6} - \frac{7}{90} a^{3} - \frac{133}{405}$, $\frac{1}{810} a^{13} + \frac{1}{90} a^{10} + \frac{31}{810} a^{7} - \frac{7}{90} a^{4} - \frac{133}{405} a$, $\frac{1}{4860} a^{14} + \frac{1}{2430} a^{13} - \frac{1}{2430} a^{12} - \frac{1}{60} a^{11} - \frac{1}{30} a^{10} + \frac{1}{30} a^{9} - \frac{239}{4860} a^{8} + \frac{31}{2430} a^{7} - \frac{31}{2430} a^{6} + \frac{9}{20} a^{5} - \frac{1}{10} a^{4} + \frac{1}{10} a^{3} + \frac{407}{2430} a^{2} - \frac{538}{1215} a + \frac{538}{1215}$, $\frac{1}{14580} a^{15} - \frac{1}{2916} a^{12} + \frac{17}{2916} a^{9} + \frac{223}{14580} a^{6} - \frac{2347}{7290} a^{3} - \frac{734}{3645}$, $\frac{1}{29160} a^{16} + \frac{13}{29160} a^{13} + \frac{247}{29160} a^{10} + \frac{781}{29160} a^{7} + \frac{1094}{3645} a^{4} - \frac{1931}{7290} a$, $\frac{1}{87480} a^{17} - \frac{1}{87480} a^{16} - \frac{1}{43740} a^{15} - \frac{1}{17496} a^{14} - \frac{49}{87480} a^{13} + \frac{1}{8748} a^{12} - \frac{307}{17496} a^{11} - \frac{3811}{87480} a^{10} + \frac{307}{8748} a^{9} - \frac{1397}{87480} a^{8} + \frac{4583}{87480} a^{7} + \frac{1397}{43740} a^{6} - \frac{3967}{43740} a^{5} - \frac{10531}{21870} a^{4} + \frac{3967}{21870} a^{3} - \frac{4417}{10935} a^{2} - \frac{1403}{4374} a - \frac{2101}{10935}$

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

Class group and class number

$C_{3}\times C_{6}$, which has order $18$ (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:  $9$
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:  \( 28469096.209551767 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_2\times C_3:S_3$ (as 18T12):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 36
The 12 conjugacy class representatives for $C_2\times C_3:S_3$
Character table for $C_2\times C_3:S_3$

Intermediate fields

\(\Q(\sqrt{33}) \), 3.1.3267.1, 3.1.13068.1, 3.1.1452.1, 3.1.108.1, 6.2.352218537.1, 6.2.69574032.1, 6.2.5635496592.1, 6.2.46574352.1, 9.1.6694969951296.1

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

Sibling fields

Galois closure: data not computed
Degree 18 sibling: 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 R ${\href{/LocalNumberField/5.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/7.6.0.1}{6} }^{3}$ R ${\href{/LocalNumberField/13.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/17.2.0.1}{2} }^{8}{,}\,{\href{/LocalNumberField/17.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/19.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/23.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/29.2.0.1}{2} }^{8}{,}\,{\href{/LocalNumberField/29.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/31.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/37.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/41.2.0.1}{2} }^{8}{,}\,{\href{/LocalNumberField/41.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/43.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/47.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/53.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/59.2.0.1}{2} }^{9}$

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$2.3.2.1$x^{3} - 2$$3$$1$$2$$S_3$$[\ ]_{3}^{2}$
2.3.2.1$x^{3} - 2$$3$$1$$2$$S_3$$[\ ]_{3}^{2}$
2.6.4.1$x^{6} + 3 x^{5} + 6 x^{4} + 3 x^{3} + 9 x + 9$$3$$2$$4$$S_3$$[\ ]_{3}^{2}$
2.6.4.1$x^{6} + 3 x^{5} + 6 x^{4} + 3 x^{3} + 9 x + 9$$3$$2$$4$$S_3$$[\ ]_{3}^{2}$
$3$3.6.7.4$x^{6} + 3 x^{2} + 3$$6$$1$$7$$S_3$$[3/2]_{2}$
3.6.7.4$x^{6} + 3 x^{2} + 3$$6$$1$$7$$S_3$$[3/2]_{2}$
3.6.7.4$x^{6} + 3 x^{2} + 3$$6$$1$$7$$S_3$$[3/2]_{2}$
$11$11.6.5.1$x^{6} - 11$$6$$1$$5$$D_{6}$$[\ ]_{6}^{2}$
11.12.10.1$x^{12} + 3146 x^{6} + 14235529$$6$$2$$10$$D_6$$[\ ]_{6}^{2}$