Properties

Label 18.0.12542912253...9827.1
Degree $18$
Signature $[0, 9]$
Discriminant $-\,3^{25}\cdot 23^{6}$
Root discriminant $13.08$
Ramified primes $3, 23$
Class number $1$
Class group Trivial
Galois group $C_3.S_3^2$ (as 18T57)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, 0, 3, -9, 21, -39, 66, -84, 105, -112, 105, -84, 66, -39, 21, -9, 3, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 + 3*x^16 - 9*x^15 + 21*x^14 - 39*x^13 + 66*x^12 - 84*x^11 + 105*x^10 - 112*x^9 + 105*x^8 - 84*x^7 + 66*x^6 - 39*x^5 + 21*x^4 - 9*x^3 + 3*x^2 + 1)
 
gp: K = bnfinit(x^18 + 3*x^16 - 9*x^15 + 21*x^14 - 39*x^13 + 66*x^12 - 84*x^11 + 105*x^10 - 112*x^9 + 105*x^8 - 84*x^7 + 66*x^6 - 39*x^5 + 21*x^4 - 9*x^3 + 3*x^2 + 1, 1)
 

Normalized defining polynomial

\( x^{18} + 3 x^{16} - 9 x^{15} + 21 x^{14} - 39 x^{13} + 66 x^{12} - 84 x^{11} + 105 x^{10} - 112 x^{9} + 105 x^{8} - 84 x^{7} + 66 x^{6} - 39 x^{5} + 21 x^{4} - 9 x^{3} + 3 x^{2} + 1 \)

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:  \(-125429122538468299827=-\,3^{25}\cdot 23^{6}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $13.08$
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:  $3, 23$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $\frac{1}{4} a^{15} + \frac{1}{4} a^{14} + \frac{1}{4} a^{13} + \frac{1}{4} a^{11} + \frac{1}{4} a^{10} + \frac{1}{4} a^{5} + \frac{1}{4} a^{4} + \frac{1}{4} a^{2} + \frac{1}{4} a + \frac{1}{4}$, $\frac{1}{1888} a^{16} - \frac{87}{944} a^{15} + \frac{389}{944} a^{14} + \frac{257}{1888} a^{13} - \frac{635}{1888} a^{12} - \frac{245}{944} a^{11} + \frac{765}{1888} a^{10} - \frac{9}{236} a^{9} + \frac{19}{118} a^{8} - \frac{9}{236} a^{7} - \frac{887}{1888} a^{6} - \frac{245}{944} a^{5} + \frac{73}{1888} a^{4} - \frac{451}{1888} a^{3} - \frac{83}{944} a^{2} + \frac{385}{944} a - \frac{235}{1888}$, $\frac{1}{7552} a^{17} - \frac{1}{7552} a^{16} + \frac{221}{1888} a^{15} - \frac{2973}{7552} a^{14} + \frac{201}{3776} a^{13} - \frac{841}{7552} a^{12} + \frac{955}{7552} a^{11} - \frac{1775}{7552} a^{10} + \frac{369}{944} a^{9} + \frac{193}{944} a^{8} + \frac{1761}{7552} a^{7} + \frac{2763}{7552} a^{6} + \frac{2151}{7552} a^{5} - \frac{1463}{3776} a^{4} - \frac{781}{7552} a^{3} - \frac{851}{1888} a^{2} + \frac{815}{7552} a - \frac{2895}{7552}$

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:  \( \frac{1555}{7552} a^{17} - \frac{907}{7552} a^{16} + \frac{1115}{1888} a^{15} - \frac{14359}{7552} a^{14} + \frac{20111}{3776} a^{13} - \frac{72899}{7552} a^{12} + \frac{114001}{7552} a^{11} - \frac{138517}{7552} a^{10} + \frac{19499}{944} a^{9} - \frac{18877}{944} a^{8} + \frac{146675}{7552} a^{7} - \frac{114727}{7552} a^{6} + \frac{85781}{7552} a^{5} - \frac{29137}{3776} a^{4} + \frac{49009}{7552} a^{3} - \frac{4997}{1888} a^{2} + \frac{10445}{7552} a + \frac{1803}{7552} \) (order $6$)
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:  \( 2115.40608662 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_3.S_3^2$ (as 18T57):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 108
The 11 conjugacy class representatives for $C_3.S_3^2$
Character table for $C_3.S_3^2$

Intermediate fields

\(\Q(\sqrt{-3}) \), 3.3.621.1, 6.0.1156923.1, 9.3.6466042647.1 x3

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

Sibling fields

Degree 9 siblings: data not computed
Degree 18 siblings: 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 ${\href{/LocalNumberField/2.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/2.2.0.1}{2} }^{3}$ R ${\href{/LocalNumberField/5.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/7.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/7.3.0.1}{3} }^{2}$ ${\href{/LocalNumberField/11.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/13.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/17.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/19.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/19.3.0.1}{3} }^{2}$ R ${\href{/LocalNumberField/29.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/29.2.0.1}{2} }^{3}$ ${\href{/LocalNumberField/31.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/37.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/37.3.0.1}{3} }^{2}$ ${\href{/LocalNumberField/41.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/41.2.0.1}{2} }^{3}$ ${\href{/LocalNumberField/43.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/43.3.0.1}{3} }^{2}$ ${\href{/LocalNumberField/47.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/47.2.0.1}{2} }^{3}$ ${\href{/LocalNumberField/53.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/59.2.0.1}{2} }^{9}$

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
3Data not computed
$23$23.2.0.1$x^{2} - x + 7$$1$$2$$0$$C_2$$[\ ]^{2}$
23.2.0.1$x^{2} - x + 7$$1$$2$$0$$C_2$$[\ ]^{2}$
23.2.0.1$x^{2} - x + 7$$1$$2$$0$$C_2$$[\ ]^{2}$
23.4.2.1$x^{4} + 299 x^{2} + 25921$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
23.4.2.1$x^{4} + 299 x^{2} + 25921$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
23.4.2.1$x^{4} + 299 x^{2} + 25921$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$