Properties

Label 18.18.2819567072...9457.1
Degree $18$
Signature $[18, 0]$
Discriminant $7^{8}\cdot 257^{9}$
Root discriminant $38.07$
Ramified primes $7, 257$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group $D_9:C_3$ (as 18T18)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![-9, -150, 391, 1723, -4431, -2794, 11003, 859, -11951, 821, 6888, -623, -2216, 144, 387, -11, -33, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 33*x^16 - 11*x^15 + 387*x^14 + 144*x^13 - 2216*x^12 - 623*x^11 + 6888*x^10 + 821*x^9 - 11951*x^8 + 859*x^7 + 11003*x^6 - 2794*x^5 - 4431*x^4 + 1723*x^3 + 391*x^2 - 150*x - 9)
 
gp: K = bnfinit(x^18 - 33*x^16 - 11*x^15 + 387*x^14 + 144*x^13 - 2216*x^12 - 623*x^11 + 6888*x^10 + 821*x^9 - 11951*x^8 + 859*x^7 + 11003*x^6 - 2794*x^5 - 4431*x^4 + 1723*x^3 + 391*x^2 - 150*x - 9, 1)
 

Normalized defining polynomial

\( x^{18} - 33 x^{16} - 11 x^{15} + 387 x^{14} + 144 x^{13} - 2216 x^{12} - 623 x^{11} + 6888 x^{10} + 821 x^{9} - 11951 x^{8} + 859 x^{7} + 11003 x^{6} - 2794 x^{5} - 4431 x^{4} + 1723 x^{3} + 391 x^{2} - 150 x - 9 \)

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

Invariants

Degree:  $18$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[18, 0]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(28195670721946845353167339457=7^{8}\cdot 257^{9}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $38.07$
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:  $7, 257$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $\frac{1}{7} a^{14} + \frac{1}{7} a^{13} + \frac{3}{7} a^{12} - \frac{3}{7} a^{11} + \frac{1}{7} a^{10} + \frac{3}{7} a^{9} + \frac{3}{7} a^{8} + \frac{3}{7} a^{7} + \frac{1}{7} a^{6} + \frac{2}{7} a^{5} - \frac{1}{7} a^{4} - \frac{1}{7} a^{2} + \frac{1}{7} a - \frac{3}{7}$, $\frac{1}{7} a^{15} + \frac{2}{7} a^{13} + \frac{1}{7} a^{12} - \frac{3}{7} a^{11} + \frac{2}{7} a^{10} - \frac{2}{7} a^{7} + \frac{1}{7} a^{6} - \frac{3}{7} a^{5} + \frac{1}{7} a^{4} - \frac{1}{7} a^{3} + \frac{2}{7} a^{2} + \frac{3}{7} a + \frac{3}{7}$, $\frac{1}{301} a^{16} + \frac{3}{43} a^{15} + \frac{20}{301} a^{14} - \frac{128}{301} a^{13} + \frac{44}{301} a^{12} - \frac{94}{301} a^{11} + \frac{109}{301} a^{10} + \frac{40}{301} a^{9} + \frac{94}{301} a^{8} + \frac{132}{301} a^{7} + \frac{15}{301} a^{6} - \frac{33}{301} a^{5} - \frac{68}{301} a^{4} - \frac{61}{301} a^{3} + \frac{118}{301} a^{2} + \frac{13}{43} a - \frac{138}{301}$, $\frac{1}{2053892695071} a^{17} + \frac{217865605}{684630898357} a^{16} - \frac{44513065399}{684630898357} a^{15} + \frac{15690548032}{2053892695071} a^{14} - \frac{246893784840}{684630898357} a^{13} + \frac{177326458737}{684630898357} a^{12} - \frac{1286523230}{47764946397} a^{11} - \frac{596734620842}{2053892695071} a^{10} - \frac{42089872179}{97804414051} a^{9} - \frac{371828267662}{2053892695071} a^{8} + \frac{377392395004}{2053892695071} a^{7} + \frac{45332509624}{2053892695071} a^{6} - \frac{760230506080}{2053892695071} a^{5} + \frac{1001610200534}{2053892695071} a^{4} + \frac{43217687647}{97804414051} a^{3} + \frac{929280140935}{2053892695071} a^{2} - \frac{3209035691}{47764946397} a + \frac{157971768179}{684630898357}$

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:  $17$
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:  \( 290535844.764 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$D_9:C_3$ (as 18T18):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 54
The 10 conjugacy class representatives for $D_9:C_3$
Character table for $D_9:C_3$

Intermediate fields

\(\Q(\sqrt{257}) \), 3.3.257.1 x3, 6.6.16974593.1, 9.9.10474291432801.1 x3

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 ${\href{/LocalNumberField/2.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/3.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/3.2.0.1}{2} }^{3}$ ${\href{/LocalNumberField/5.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/5.2.0.1}{2} }^{3}$ R ${\href{/LocalNumberField/11.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/13.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/17.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/19.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/19.2.0.1}{2} }^{3}$ ${\href{/LocalNumberField/23.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/29.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/31.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/37.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/37.2.0.1}{2} }^{3}$ ${\href{/LocalNumberField/41.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/43.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/47.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/47.2.0.1}{2} }^{3}$ ${\href{/LocalNumberField/53.6.0.1}{6} }^{2}{,}\,{\href{/LocalNumberField/53.2.0.1}{2} }^{3}$ ${\href{/LocalNumberField/59.9.0.1}{9} }^{2}$

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
$7$7.2.0.1$x^{2} - x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
7.2.0.1$x^{2} - x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
7.2.0.1$x^{2} - x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
7.6.4.3$x^{6} + 56 x^{3} + 1323$$3$$2$$4$$C_6$$[\ ]_{3}^{2}$
7.6.4.3$x^{6} + 56 x^{3} + 1323$$3$$2$$4$$C_6$$[\ ]_{3}^{2}$
257Data not computed