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Properties

Label 18.0.76570728557...0688.1
Degree $18$
Signature $[0, 9]$
Discriminant $-\,2^{12}\cdot 83^{9}$
Root discriminant $14.46$
Ramified primes $2, 83$
Class number $1$
Class group Trivial
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![1, -3, 10, -25, 47, -74, 101, -135, 177, -182, 177, -135, 101, -74, 47, -25, 10, -3, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 3*x^17 + 10*x^16 - 25*x^15 + 47*x^14 - 74*x^13 + 101*x^12 - 135*x^11 + 177*x^10 - 182*x^9 + 177*x^8 - 135*x^7 + 101*x^6 - 74*x^5 + 47*x^4 - 25*x^3 + 10*x^2 - 3*x + 1)
 
gp: K = bnfinit(x^18 - 3*x^17 + 10*x^16 - 25*x^15 + 47*x^14 - 74*x^13 + 101*x^12 - 135*x^11 + 177*x^10 - 182*x^9 + 177*x^8 - 135*x^7 + 101*x^6 - 74*x^5 + 47*x^4 - 25*x^3 + 10*x^2 - 3*x + 1, 1)
 

Normalized defining polynomial

\( x^{18} - 3 x^{17} + 10 x^{16} - 25 x^{15} + 47 x^{14} - 74 x^{13} + 101 x^{12} - 135 x^{11} + 177 x^{10} - 182 x^{9} + 177 x^{8} - 135 x^{7} + 101 x^{6} - 74 x^{5} + 47 x^{4} - 25 x^{3} + 10 x^{2} - 3 x + 1 \)

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:  \(-765707285575845490688=-\,2^{12}\cdot 83^{9}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $14.46$
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:  $2, 83$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $\frac{1}{2} a^{9} - \frac{1}{2} a^{6} - \frac{1}{2} a^{3} - \frac{1}{2}$, $\frac{1}{2} a^{10} - \frac{1}{2} a^{7} - \frac{1}{2} a^{4} - \frac{1}{2} a$, $\frac{1}{4} a^{11} - \frac{1}{4} a^{9} - \frac{1}{4} a^{8} - \frac{1}{4} a^{6} + \frac{1}{4} a^{5} - \frac{1}{2} a^{4} + \frac{1}{4} a^{3} + \frac{1}{4} a^{2} - \frac{1}{2} a - \frac{1}{4}$, $\frac{1}{8} a^{12} - \frac{1}{8} a^{11} - \frac{1}{8} a^{10} - \frac{1}{4} a^{9} - \frac{3}{8} a^{8} + \frac{3}{8} a^{7} - \frac{1}{2} a^{6} + \frac{1}{8} a^{5} - \frac{1}{8} a^{4} + \frac{1}{4} a^{3} - \frac{3}{8} a^{2} - \frac{3}{8} a - \frac{1}{8}$, $\frac{1}{8} a^{13} + \frac{1}{8} a^{10} + \frac{1}{8} a^{9} - \frac{1}{4} a^{8} + \frac{3}{8} a^{7} + \frac{3}{8} a^{6} + \frac{1}{4} a^{5} + \frac{1}{8} a^{4} + \frac{1}{8} a^{3} - \frac{1}{2} a^{2} - \frac{1}{2} a - \frac{3}{8}$, $\frac{1}{16} a^{14} - \frac{1}{16} a^{13} + \frac{1}{16} a^{11} + \frac{1}{16} a^{9} + \frac{5}{16} a^{8} + \frac{3}{16} a^{6} + \frac{7}{16} a^{5} + \frac{7}{16} a^{3} - \frac{7}{16} a + \frac{7}{16}$, $\frac{1}{16} a^{15} - \frac{1}{16} a^{13} - \frac{1}{16} a^{12} - \frac{1}{16} a^{11} + \frac{3}{16} a^{10} - \frac{1}{8} a^{9} - \frac{1}{16} a^{8} - \frac{3}{16} a^{7} + \frac{3}{8} a^{6} + \frac{1}{16} a^{5} + \frac{1}{16} a^{4} - \frac{1}{16} a^{3} - \frac{5}{16} a^{2} - \frac{1}{8} a - \frac{3}{16}$, $\frac{1}{3040} a^{16} - \frac{49}{3040} a^{15} - \frac{17}{3040} a^{14} - \frac{9}{190} a^{13} - \frac{1}{20} a^{12} - \frac{87}{760} a^{11} - \frac{269}{3040} a^{10} + \frac{617}{3040} a^{9} - \frac{193}{1520} a^{8} + \frac{1377}{3040} a^{7} - \frac{269}{3040} a^{6} - \frac{93}{190} a^{5} - \frac{39}{80} a^{4} - \frac{131}{760} a^{3} + \frac{1123}{3040} a^{2} - \frac{809}{3040} a - \frac{189}{3040}$, $\frac{1}{3040} a^{17} + \frac{13}{760} a^{15} - \frac{27}{3040} a^{14} + \frac{3}{760} a^{13} - \frac{3}{1520} a^{12} - \frac{221}{3040} a^{11} - \frac{107}{1520} a^{10} - \frac{743}{3040} a^{9} + \frac{57}{160} a^{8} - \frac{313}{1520} a^{7} + \frac{1481}{3040} a^{6} + \frac{613}{1520} a^{5} + \frac{287}{760} a^{4} + \frac{147}{3040} a^{3} + \frac{14}{95} a^{2} + \frac{35}{76} a + \frac{999}{3040}$

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:  \( 1527.29829068 \)
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

\(\Q(\sqrt{-83}) \), 3.1.83.1 x3, 6.0.571787.1, 9.1.3037332544.1 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 R ${\href{/LocalNumberField/3.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/5.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/7.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/11.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/13.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/17.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/19.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/23.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/29.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/31.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/37.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/41.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/43.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/47.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/53.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/59.9.0.1}{9} }^{2}$

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
$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}$
2.6.4.1$x^{6} + 3 x^{5} + 6 x^{4} + 3 x^{3} + 9 x + 9$$3$$2$$4$$S_3$$[\ ]_{3}^{2}$
$83$83.2.1.2$x^{2} + 249$$2$$1$$1$$C_2$$[\ ]_{2}$
83.2.1.2$x^{2} + 249$$2$$1$$1$$C_2$$[\ ]_{2}$
83.2.1.2$x^{2} + 249$$2$$1$$1$$C_2$$[\ ]_{2}$
83.2.1.2$x^{2} + 249$$2$$1$$1$$C_2$$[\ ]_{2}$
83.2.1.2$x^{2} + 249$$2$$1$$1$$C_2$$[\ ]_{2}$
83.2.1.2$x^{2} + 249$$2$$1$$1$$C_2$$[\ ]_{2}$
83.2.1.2$x^{2} + 249$$2$$1$$1$$C_2$$[\ ]_{2}$
83.2.1.2$x^{2} + 249$$2$$1$$1$$C_2$$[\ ]_{2}$
83.2.1.2$x^{2} + 249$$2$$1$$1$$C_2$$[\ ]_{2}$