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Properties

Label 18.8.72096958561...2443.1
Degree $18$
Signature $[8, 5]$
Discriminant $-\,3^{27}\cdot 73^{4}\cdot 577^{2}$
Root discriminant $27.32$
Ramified primes $3, 73, 577$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group 18T768

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, 21, 12, -1017, -435, 1917, 556, -741, -558, -44, 153, 114, -23, 3, -3, -16, 9, -3, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 3*x^17 + 9*x^16 - 16*x^15 - 3*x^14 + 3*x^13 - 23*x^12 + 114*x^11 + 153*x^10 - 44*x^9 - 558*x^8 - 741*x^7 + 556*x^6 + 1917*x^5 - 435*x^4 - 1017*x^3 + 12*x^2 + 21*x + 1)
 
gp: K = bnfinit(x^18 - 3*x^17 + 9*x^16 - 16*x^15 - 3*x^14 + 3*x^13 - 23*x^12 + 114*x^11 + 153*x^10 - 44*x^9 - 558*x^8 - 741*x^7 + 556*x^6 + 1917*x^5 - 435*x^4 - 1017*x^3 + 12*x^2 + 21*x + 1, 1)
 

Normalized defining polynomial

\( x^{18} - 3 x^{17} + 9 x^{16} - 16 x^{15} - 3 x^{14} + 3 x^{13} - 23 x^{12} + 114 x^{11} + 153 x^{10} - 44 x^{9} - 558 x^{8} - 741 x^{7} + 556 x^{6} + 1917 x^{5} - 435 x^{4} - 1017 x^{3} + 12 x^{2} + 21 x + 1 \)

magma: DefiningPolynomial(K);
 
sage: K.defining_polynomial()
 
gp: K.pol
 

Invariants

Degree:  $18$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[8, 5]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(-72096958561753534235452443=-\,3^{27}\cdot 73^{4}\cdot 577^{2}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $27.32$
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:  $3, 73, 577$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $a^{16}$, $\frac{1}{4651890768185235910675721} a^{17} + \frac{663258614985807875341715}{4651890768185235910675721} a^{16} - \frac{11522065194614896567191}{4651890768185235910675721} a^{15} + \frac{2246041577697393398462863}{4651890768185235910675721} a^{14} + \frac{1077233512492037482640149}{4651890768185235910675721} a^{13} + \frac{1405279157986964727561450}{4651890768185235910675721} a^{12} + \frac{1645567369905475099259526}{4651890768185235910675721} a^{11} + \frac{999687553175165983555552}{4651890768185235910675721} a^{10} + \frac{435012769999337627957111}{4651890768185235910675721} a^{9} - \frac{224268536483048076555822}{4651890768185235910675721} a^{8} - \frac{2131041067025709308842012}{4651890768185235910675721} a^{7} - \frac{1567189742613676664906067}{4651890768185235910675721} a^{6} - \frac{428410856632140239862923}{4651890768185235910675721} a^{5} + \frac{28374913801193577421323}{4651890768185235910675721} a^{4} + \frac{328435273883142914980357}{4651890768185235910675721} a^{3} - \frac{1971796171792083153161490}{4651890768185235910675721} a^{2} - \frac{1039766663534510628028355}{4651890768185235910675721} a + \frac{1136860495128099751727841}{4651890768185235910675721}$

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

Class group and class number

Trivial group, which has order $1$ (assuming GRH)

magma: ClassGroup(K);
 
sage: K.class_group().invariants()
 
gp: K.clgp
 

Unit group

magma: UK, f := UnitGroup(K);
 
sage: UK = K.unit_group()
 
Rank:  $12$
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 (assuming GRH)
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 1315526.46313 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

18T768:

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 82944
The 110 conjugacy class representatives for t18n768 are not computed
Character table for t18n768 is not computed

Intermediate fields

\(\Q(\zeta_{9})^+\), 9.9.22384826361.1

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

Sibling fields

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 $18$ R $18$ ${\href{/LocalNumberField/7.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/11.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/13.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/17.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/17.4.0.1}{4} }{,}\,{\href{/LocalNumberField/17.1.0.1}{1} }^{2}$ ${\href{/LocalNumberField/19.4.0.1}{4} }{,}\,{\href{/LocalNumberField/19.3.0.1}{3} }^{2}{,}\,{\href{/LocalNumberField/19.2.0.1}{2} }^{3}{,}\,{\href{/LocalNumberField/19.1.0.1}{1} }^{2}$ $18$ $18$ ${\href{/LocalNumberField/31.12.0.1}{12} }{,}\,{\href{/LocalNumberField/31.6.0.1}{6} }$ ${\href{/LocalNumberField/37.4.0.1}{4} }{,}\,{\href{/LocalNumberField/37.3.0.1}{3} }^{4}{,}\,{\href{/LocalNumberField/37.2.0.1}{2} }$ ${\href{/LocalNumberField/41.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/43.9.0.1}{9} }^{2}$ $18$ ${\href{/LocalNumberField/53.4.0.1}{4} }^{3}{,}\,{\href{/LocalNumberField/53.1.0.1}{1} }^{6}$ ${\href{/LocalNumberField/59.6.0.1}{6} }^{3}$

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
73Data not computed
577Data not computed