Properties

Label 18.0.53137762492...9375.1
Degree $18$
Signature $[0, 9]$
Discriminant $-\,5^{9}\cdot 67^{9}$
Root discriminant $18.30$
Ramified primes $5, 67$
Class number $2$
Class group $[2]$
Galois group $D_9$ (as 18T5)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![335, 0, 341, 0, 206, 0, -446, 0, 279, 0, -145, 0, 64, 0, -6, 0, -4, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 4*x^16 - 6*x^14 + 64*x^12 - 145*x^10 + 279*x^8 - 446*x^6 + 206*x^4 + 341*x^2 + 335)
 
gp: K = bnfinit(x^18 - 4*x^16 - 6*x^14 + 64*x^12 - 145*x^10 + 279*x^8 - 446*x^6 + 206*x^4 + 341*x^2 + 335, 1)
 

Normalized defining polynomial

\( x^{18} - 4 x^{16} - 6 x^{14} + 64 x^{12} - 145 x^{10} + 279 x^{8} - 446 x^{6} + 206 x^{4} + 341 x^{2} + 335 \)

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:  \(-53137762492763568359375=-\,5^{9}\cdot 67^{9}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $18.30$
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:  $5, 67$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $\frac{1}{2} a^{9} - \frac{1}{2} a^{5} - \frac{1}{2} a^{4} - \frac{1}{2} a - \frac{1}{2}$, $\frac{1}{10} a^{10} + \frac{3}{10} a^{6} - \frac{1}{2} a^{5} + \frac{1}{10} a^{2} - \frac{1}{2} a$, $\frac{1}{10} a^{11} + \frac{3}{10} a^{7} - \frac{1}{2} a^{6} + \frac{1}{10} a^{3} - \frac{1}{2} a^{2}$, $\frac{1}{10} a^{12} + \frac{3}{10} a^{8} - \frac{1}{2} a^{7} + \frac{1}{10} a^{4} - \frac{1}{2} a^{3}$, $\frac{1}{10} a^{13} - \frac{1}{5} a^{9} - \frac{1}{2} a^{8} - \frac{2}{5} a^{5} - \frac{1}{2} a - \frac{1}{2}$, $\frac{1}{1150} a^{14} + \frac{3}{1150} a^{12} - \frac{8}{575} a^{10} - \frac{141}{1150} a^{8} - \frac{1}{2} a^{7} + \frac{257}{575} a^{6} - \frac{1}{2} a^{5} + \frac{99}{575} a^{4} - \frac{1}{2} a^{3} + \frac{531}{1150} a^{2} + \frac{17}{230}$, $\frac{1}{1150} a^{15} + \frac{3}{1150} a^{13} - \frac{8}{575} a^{11} - \frac{141}{1150} a^{9} - \frac{1}{2} a^{8} + \frac{257}{575} a^{7} - \frac{1}{2} a^{6} + \frac{99}{575} a^{5} - \frac{1}{2} a^{4} + \frac{531}{1150} a^{3} + \frac{17}{230} a$, $\frac{1}{145308250} a^{16} - \frac{5383}{145308250} a^{14} - \frac{5160699}{145308250} a^{12} + \frac{489246}{14530825} a^{10} + \frac{351989}{785450} a^{8} - \frac{46957531}{145308250} a^{6} - \frac{1}{2} a^{5} - \frac{1613297}{145308250} a^{4} - \frac{1}{2} a^{3} - \frac{4806628}{72654125} a^{2} - \frac{215877}{29061650}$, $\frac{1}{145308250} a^{17} - \frac{5383}{145308250} a^{15} - \frac{5160699}{145308250} a^{13} + \frac{489246}{14530825} a^{11} - \frac{20368}{392725} a^{9} - \frac{46957531}{145308250} a^{7} - \frac{1}{2} a^{6} + \frac{35520414}{72654125} a^{5} - \frac{4806628}{72654125} a^{3} + \frac{7157474}{14530825} a - \frac{1}{2}$

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

Class group and class number

$C_{2}$, which has order $2$

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:  \( 14588.8980085 \)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$D_9$ (as 18T5):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 18
The 6 conjugacy class representatives for $D_9$
Character table for $D_9$

Intermediate fields

\(\Q(\sqrt{-335}) \), 3.1.335.1 x3, 6.0.37595375.1, 9.1.12594450625.1 x9

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

Sibling fields

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 ${\href{/LocalNumberField/2.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/3.9.0.1}{9} }^{2}$ R ${\href{/LocalNumberField/7.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/11.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/13.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/17.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/19.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/23.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/29.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/31.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/37.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/41.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/43.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/47.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/53.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/59.9.0.1}{9} }^{2}$

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
$5$5.2.1.2$x^{2} + 10$$2$$1$$1$$C_2$$[\ ]_{2}$
5.2.1.2$x^{2} + 10$$2$$1$$1$$C_2$$[\ ]_{2}$
5.2.1.2$x^{2} + 10$$2$$1$$1$$C_2$$[\ ]_{2}$
5.2.1.2$x^{2} + 10$$2$$1$$1$$C_2$$[\ ]_{2}$
5.2.1.2$x^{2} + 10$$2$$1$$1$$C_2$$[\ ]_{2}$
5.2.1.2$x^{2} + 10$$2$$1$$1$$C_2$$[\ ]_{2}$
5.2.1.2$x^{2} + 10$$2$$1$$1$$C_2$$[\ ]_{2}$
5.2.1.2$x^{2} + 10$$2$$1$$1$$C_2$$[\ ]_{2}$
5.2.1.2$x^{2} + 10$$2$$1$$1$$C_2$$[\ ]_{2}$
$67$67.2.1.1$x^{2} - 67$$2$$1$$1$$C_2$$[\ ]_{2}$
67.2.1.1$x^{2} - 67$$2$$1$$1$$C_2$$[\ ]_{2}$
67.2.1.1$x^{2} - 67$$2$$1$$1$$C_2$$[\ ]_{2}$
67.2.1.1$x^{2} - 67$$2$$1$$1$$C_2$$[\ ]_{2}$
67.2.1.1$x^{2} - 67$$2$$1$$1$$C_2$$[\ ]_{2}$
67.2.1.1$x^{2} - 67$$2$$1$$1$$C_2$$[\ ]_{2}$
67.2.1.1$x^{2} - 67$$2$$1$$1$$C_2$$[\ ]_{2}$
67.2.1.1$x^{2} - 67$$2$$1$$1$$C_2$$[\ ]_{2}$
67.2.1.1$x^{2} - 67$$2$$1$$1$$C_2$$[\ ]_{2}$