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Properties

Label 18.0.36595840381...1871.1
Degree $18$
Signature $[0, 9]$
Discriminant $-\,7^{12}\cdot 31^{9}$
Root discriminant $20.37$
Ramified primes $7, 31$
Class number $3$
Class group $[3]$
Galois group $S_3 \times C_3$ (as 18T3)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, -6, 33, -93, 193, -294, 454, -384, 476, -138, 224, -66, 174, -126, 79, -30, 17, -3, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 3*x^17 + 17*x^16 - 30*x^15 + 79*x^14 - 126*x^13 + 174*x^12 - 66*x^11 + 224*x^10 - 138*x^9 + 476*x^8 - 384*x^7 + 454*x^6 - 294*x^5 + 193*x^4 - 93*x^3 + 33*x^2 - 6*x + 1)
 
gp: K = bnfinit(x^18 - 3*x^17 + 17*x^16 - 30*x^15 + 79*x^14 - 126*x^13 + 174*x^12 - 66*x^11 + 224*x^10 - 138*x^9 + 476*x^8 - 384*x^7 + 454*x^6 - 294*x^5 + 193*x^4 - 93*x^3 + 33*x^2 - 6*x + 1, 1)
 

Normalized defining polynomial

\( x^{18} - 3 x^{17} + 17 x^{16} - 30 x^{15} + 79 x^{14} - 126 x^{13} + 174 x^{12} - 66 x^{11} + 224 x^{10} - 138 x^{9} + 476 x^{8} - 384 x^{7} + 454 x^{6} - 294 x^{5} + 193 x^{4} - 93 x^{3} + 33 x^{2} - 6 x + 1 \)

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:  \(-365958403811771477871871=-\,7^{12}\cdot 31^{9}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $20.37$
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:  $7, 31$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois over $\Q$.
This is not a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $\frac{1}{2} a^{7} - \frac{1}{2}$, $\frac{1}{2} a^{8} - \frac{1}{2} a$, $\frac{1}{2} a^{9} - \frac{1}{2} a^{2}$, $\frac{1}{2} a^{10} - \frac{1}{2} a^{3}$, $\frac{1}{2} a^{11} - \frac{1}{2} a^{4}$, $\frac{1}{2} a^{12} - \frac{1}{2} a^{5}$, $\frac{1}{8} a^{13} + \frac{1}{8} a^{12} + \frac{1}{8} a^{11} - \frac{1}{8} a^{10} - \frac{1}{8} a^{9} - \frac{1}{8} a^{8} + \frac{1}{8} a^{7} + \frac{3}{8} a^{6} - \frac{1}{8} a^{5} + \frac{3}{8} a^{4} - \frac{3}{8} a^{3} - \frac{3}{8} a^{2} + \frac{1}{8} a - \frac{1}{8}$, $\frac{1}{16} a^{14} - \frac{1}{4} a^{12} + \frac{1}{8} a^{11} - \frac{1}{4} a^{10} - \frac{1}{4} a^{9} + \frac{1}{8} a^{8} - \frac{1}{8} a^{7} + \frac{1}{4} a^{6} - \frac{1}{2} a^{5} - \frac{1}{8} a^{4} - \frac{1}{4} a^{3} - \frac{1}{8} a + \frac{5}{16}$, $\frac{1}{16} a^{15} - \frac{1}{8} a^{12} - \frac{1}{8} a^{9} + \frac{1}{8} a^{8} + \frac{1}{4} a^{6} + \frac{1}{8} a^{5} - \frac{1}{2} a^{4} - \frac{1}{4} a^{3} + \frac{1}{8} a^{2} + \frac{1}{16} a + \frac{1}{4}$, $\frac{1}{932528} a^{16} - \frac{4081}{233132} a^{15} - \frac{1747}{932528} a^{14} + \frac{2695}{116566} a^{13} + \frac{41903}{466264} a^{12} + \frac{2661}{233132} a^{11} - \frac{22465}{116566} a^{10} + \frac{4375}{233132} a^{9} - \frac{20759}{116566} a^{8} - \frac{14569}{233132} a^{7} - \frac{96239}{233132} a^{6} + \frac{192207}{466264} a^{5} + \frac{20299}{58283} a^{4} + \frac{39297}{116566} a^{3} + \frac{265787}{932528} a^{2} - \frac{28155}{58283} a - \frac{292225}{932528}$, $\frac{1}{7359510976} a^{17} + \frac{1423}{3679755488} a^{16} - \frac{29094617}{7359510976} a^{15} + \frac{44222809}{7359510976} a^{14} - \frac{11345535}{229984718} a^{13} + \frac{796932985}{3679755488} a^{12} + \frac{13647201}{114992359} a^{11} + \frac{223753335}{3679755488} a^{10} - \frac{50731937}{3679755488} a^{9} + \frac{14102505}{1839877744} a^{8} + \frac{43208457}{459969436} a^{7} - \frac{3675651}{114992359} a^{6} + \frac{609234955}{3679755488} a^{5} - \frac{138105681}{459969436} a^{4} + \frac{226646113}{7359510976} a^{3} + \frac{541316541}{1839877744} a^{2} - \frac{807770963}{7359510976} a + \frac{58200295}{7359510976}$

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

Class group and class number

$C_{3}$, which has order $3$

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:  \( 7064.88214687 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_3\times S_3$ (as 18T3):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 18
The 9 conjugacy class representatives for $S_3 \times C_3$
Character table for $S_3 \times C_3$

Intermediate fields

\(\Q(\sqrt{-31}) \), 3.1.31.1 x3, \(\Q(\zeta_{7})^+\), 6.0.29791.1, 6.0.71528191.2 x2, 6.0.71528191.1, 9.3.3504881359.1 x3

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

Sibling fields

Degree 6 sibling: 6.0.71528191.2
Degree 9 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 ${\href{/LocalNumberField/2.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/3.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/5.3.0.1}{3} }^{6}$ R ${\href{/LocalNumberField/11.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/13.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/17.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/19.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/23.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/29.2.0.1}{2} }^{9}$ R ${\href{/LocalNumberField/37.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/41.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/43.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/47.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/53.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/59.3.0.1}{3} }^{6}$

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
$7$7.9.6.1$x^{9} + 42 x^{6} + 539 x^{3} + 2744$$3$$3$$6$$C_3^2$$[\ ]_{3}^{3}$
7.9.6.1$x^{9} + 42 x^{6} + 539 x^{3} + 2744$$3$$3$$6$$C_3^2$$[\ ]_{3}^{3}$
$31$31.6.3.2$x^{6} - 961 x^{2} + 268119$$2$$3$$3$$C_6$$[\ ]_{2}^{3}$
31.6.3.2$x^{6} - 961 x^{2} + 268119$$2$$3$$3$$C_6$$[\ ]_{2}^{3}$
31.6.3.2$x^{6} - 961 x^{2} + 268119$$2$$3$$3$$C_6$$[\ ]_{2}^{3}$