Properties

Label 18.0.86675003008...7168.2
Degree $18$
Signature $[0, 9]$
Discriminant $-\,2^{33}\cdot 3^{6}\cdot 7^{12}$
Root discriminant $18.81$
Ramified primes $2, 3, 7$
Class number $1$
Class group Trivial
Galois group $S_3 \times C_6$ (as 18T6)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, -2, 13, 18, 6, -16, 29, 20, -31, 98, 151, -274, 135, -74, 54, -18, 6, -4, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 4*x^17 + 6*x^16 - 18*x^15 + 54*x^14 - 74*x^13 + 135*x^12 - 274*x^11 + 151*x^10 + 98*x^9 - 31*x^8 + 20*x^7 + 29*x^6 - 16*x^5 + 6*x^4 + 18*x^3 + 13*x^2 - 2*x + 1)
 
gp: K = bnfinit(x^18 - 4*x^17 + 6*x^16 - 18*x^15 + 54*x^14 - 74*x^13 + 135*x^12 - 274*x^11 + 151*x^10 + 98*x^9 - 31*x^8 + 20*x^7 + 29*x^6 - 16*x^5 + 6*x^4 + 18*x^3 + 13*x^2 - 2*x + 1, 1)
 

Normalized defining polynomial

\( x^{18} - 4 x^{17} + 6 x^{16} - 18 x^{15} + 54 x^{14} - 74 x^{13} + 135 x^{12} - 274 x^{11} + 151 x^{10} + 98 x^{9} - 31 x^{8} + 20 x^{7} + 29 x^{6} - 16 x^{5} + 6 x^{4} + 18 x^{3} + 13 x^{2} - 2 x + 1 \)

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:  \(-86675003008018355847168=-\,2^{33}\cdot 3^{6}\cdot 7^{12}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $18.81$
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:  $2, 3, 7$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $\frac{1}{129} a^{15} + \frac{32}{129} a^{14} + \frac{34}{129} a^{13} - \frac{62}{129} a^{12} - \frac{49}{129} a^{11} - \frac{38}{129} a^{10} - \frac{17}{129} a^{9} - \frac{50}{129} a^{8} - \frac{47}{129} a^{7} + \frac{56}{129} a^{6} + \frac{38}{129} a^{5} + \frac{8}{43} a^{4} + \frac{50}{129} a^{3} + \frac{18}{43} a^{2} + \frac{35}{129} a + \frac{1}{129}$, $\frac{1}{129} a^{16} + \frac{14}{43} a^{14} + \frac{11}{129} a^{13} - \frac{6}{43} a^{11} + \frac{38}{129} a^{10} - \frac{22}{129} a^{9} + \frac{5}{129} a^{8} + \frac{4}{43} a^{7} + \frac{52}{129} a^{6} - \frac{31}{129} a^{5} + \frac{56}{129} a^{4} + \frac{2}{129} a^{3} - \frac{16}{129} a^{2} + \frac{14}{43} a - \frac{32}{129}$, $\frac{1}{506072874077823} a^{17} + \frac{88931764786}{38928682621371} a^{16} + \frac{577510445401}{506072874077823} a^{15} - \frac{42289167745676}{506072874077823} a^{14} + \frac{5929823852710}{12976227540457} a^{13} + \frac{193961441769151}{506072874077823} a^{12} + \frac{117295909560799}{506072874077823} a^{11} - \frac{146271720201784}{506072874077823} a^{10} + \frac{214015197025814}{506072874077823} a^{9} - \frac{68211677146751}{168690958025941} a^{8} - \frac{155381349836320}{506072874077823} a^{7} - \frac{17387217403459}{506072874077823} a^{6} - \frac{67808726474584}{168690958025941} a^{5} + \frac{6014815856401}{506072874077823} a^{4} + \frac{59830138081258}{168690958025941} a^{3} - \frac{34987260465073}{506072874077823} a^{2} + \frac{66544043009192}{168690958025941} a + \frac{204074460781298}{506072874077823}$

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

Class group and class number

Trivial group, which has order $1$

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
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 9688.268698021906 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_6\times S_3$ (as 18T6):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 36
The 18 conjugacy class representatives for $S_3 \times C_6$
Character table for $S_3 \times C_6$

Intermediate fields

\(\Q(\sqrt{-2}) \), \(\Q(\zeta_{7})^+\), 3.1.1176.1, 6.0.44255232.1, 6.0.1229312.1, 9.3.1626379776.1

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 12 sibling: 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 ${\href{/LocalNumberField/5.6.0.1}{6} }^{3}$ R ${\href{/LocalNumberField/11.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/13.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/17.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/17.3.0.1}{3} }^{2}$ ${\href{/LocalNumberField/19.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/19.3.0.1}{3} }^{2}$ ${\href{/LocalNumberField/23.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/29.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/31.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/37.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/41.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/41.1.0.1}{1} }^{6}$ ${\href{/LocalNumberField/43.2.0.1}{2} }^{6}{,}\,{\href{/LocalNumberField/43.1.0.1}{1} }^{6}$ ${\href{/LocalNumberField/47.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/53.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/59.3.0.1}{3} }^{6}$

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$2.6.9.5$x^{6} - 4 x^{4} + 4 x^{2} + 8$$2$$3$$9$$C_6$$[3]^{3}$
2.12.24.307$x^{12} + 28 x^{11} - 2 x^{10} + 16 x^{9} + 26 x^{8} + 8 x^{7} + 20 x^{6} - 24 x^{5} - 8 x^{4} + 32 x^{3} + 32 x^{2} + 32 x + 24$$4$$3$$24$$C_6\times C_2$$[2, 3]^{3}$
$3$3.3.0.1$x^{3} - x + 1$$1$$3$$0$$C_3$$[\ ]^{3}$
3.3.0.1$x^{3} - x + 1$$1$$3$$0$$C_3$$[\ ]^{3}$
3.6.3.1$x^{6} - 6 x^{4} + 9 x^{2} - 27$$2$$3$$3$$C_6$$[\ ]_{2}^{3}$
3.6.3.1$x^{6} - 6 x^{4} + 9 x^{2} - 27$$2$$3$$3$$C_6$$[\ ]_{2}^{3}$
7Data not computed