Properties

Label 18.0.77615347601...1875.2
Degree $18$
Signature $[0, 9]$
Discriminant $-\,3^{44}\cdot 5^{9}\cdot 7^{9}$
Root discriminant $86.76$
Ramified primes $3, 5, 7$
Class number $248022$ (GRH)
Class group $[9, 27558]$ (GRH)
Galois group $C_{18}$ (as 18T1)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![2049933909, -1193424489, 1530279351, -733296564, 524296044, -210931569, 108462921, -36981954, 14929371, -4312778, 1416780, -342630, 92400, -18144, 3960, -588, 99, -9, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 9*x^17 + 99*x^16 - 588*x^15 + 3960*x^14 - 18144*x^13 + 92400*x^12 - 342630*x^11 + 1416780*x^10 - 4312778*x^9 + 14929371*x^8 - 36981954*x^7 + 108462921*x^6 - 210931569*x^5 + 524296044*x^4 - 733296564*x^3 + 1530279351*x^2 - 1193424489*x + 2049933909)
 
gp: K = bnfinit(x^18 - 9*x^17 + 99*x^16 - 588*x^15 + 3960*x^14 - 18144*x^13 + 92400*x^12 - 342630*x^11 + 1416780*x^10 - 4312778*x^9 + 14929371*x^8 - 36981954*x^7 + 108462921*x^6 - 210931569*x^5 + 524296044*x^4 - 733296564*x^3 + 1530279351*x^2 - 1193424489*x + 2049933909, 1)
 

Normalized defining polynomial

\( x^{18} - 9 x^{17} + 99 x^{16} - 588 x^{15} + 3960 x^{14} - 18144 x^{13} + 92400 x^{12} - 342630 x^{11} + 1416780 x^{10} - 4312778 x^{9} + 14929371 x^{8} - 36981954 x^{7} + 108462921 x^{6} - 210931569 x^{5} + 524296044 x^{4} - 733296564 x^{3} + 1530279351 x^{2} - 1193424489 x + 2049933909 \)

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:  \(-77615347601079862368096390169921875=-\,3^{44}\cdot 5^{9}\cdot 7^{9}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $86.76$
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:  $3, 5, 7$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(945=3^{3}\cdot 5\cdot 7\)
Dirichlet character group:    $\lbrace$$\chi_{945}(1,·)$, $\chi_{945}(454,·)$, $\chi_{945}(769,·)$, $\chi_{945}(841,·)$, $\chi_{945}(139,·)$, $\chi_{945}(526,·)$, $\chi_{945}(211,·)$, $\chi_{945}(664,·)$, $\chi_{945}(349,·)$, $\chi_{945}(736,·)$, $\chi_{945}(34,·)$, $\chi_{945}(421,·)$, $\chi_{945}(874,·)$, $\chi_{945}(559,·)$, $\chi_{945}(244,·)$, $\chi_{945}(631,·)$, $\chi_{945}(316,·)$, $\chi_{945}(106,·)$$\rbrace$
This is a CM field.

Integral basis (with respect to field generator \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $\frac{1}{109} a^{16} + \frac{6}{109} a^{15} + \frac{15}{109} a^{14} + \frac{10}{109} a^{13} - \frac{26}{109} a^{12} + \frac{23}{109} a^{10} - \frac{25}{109} a^{9} - \frac{19}{109} a^{8} - \frac{52}{109} a^{7} - \frac{13}{109} a^{6} + \frac{26}{109} a^{5} + \frac{53}{109} a^{3} - \frac{28}{109} a^{2} + \frac{14}{109} a - \frac{30}{109}$, $\frac{1}{22095789080844660822518693516790949765794861210280688101} a^{17} + \frac{64751859086685796180155069850270251582421724953562175}{22095789080844660822518693516790949765794861210280688101} a^{16} - \frac{3417576433363253460081377604352228172424857753458657058}{22095789080844660822518693516790949765794861210280688101} a^{15} - \frac{7258572543546173223769487375793613544814643732543961172}{22095789080844660822518693516790949765794861210280688101} a^{14} + \frac{3898212959671491656104041688335619617407463028778290046}{22095789080844660822518693516790949765794861210280688101} a^{13} - \frac{5253758196281990188296628715387496459787639034529570927}{22095789080844660822518693516790949765794861210280688101} a^{12} + \frac{9920127807612233943117714645115974621761311424011169728}{22095789080844660822518693516790949765794861210280688101} a^{11} - \frac{4200596618411459846849822312667996016010826530764511649}{22095789080844660822518693516790949765794861210280688101} a^{10} - \frac{272586505164772130900321507523244232198986923054597016}{22095789080844660822518693516790949765794861210280688101} a^{9} - \frac{3151279588865256998658793187490243093491698390411965432}{22095789080844660822518693516790949765794861210280688101} a^{8} + \frac{4051504912058856389097276495198265719817039145014555031}{22095789080844660822518693516790949765794861210280688101} a^{7} - \frac{755731808374761284661213683382645641842596359186399332}{22095789080844660822518693516790949765794861210280688101} a^{6} + \frac{10748275921264310567977748677390296509959846820245187860}{22095789080844660822518693516790949765794861210280688101} a^{5} - \frac{6247592087240663043075873532800472306749843788089011770}{22095789080844660822518693516790949765794861210280688101} a^{4} + \frac{2021125168029431200613340242440899554096207340624263933}{22095789080844660822518693516790949765794861210280688101} a^{3} - \frac{10353378888115628488142436817866766740317160228409001856}{22095789080844660822518693516790949765794861210280688101} a^{2} + \frac{8166390487164151480842557481434895228751784631950655751}{22095789080844660822518693516790949765794861210280688101} a + \frac{5656935318739044805516334951692476495531693616668407772}{22095789080844660822518693516790949765794861210280688101}$

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

Class group and class number

$C_{9}\times C_{27558}$, which has order $248022$ (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:  $8$
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 (assuming GRH)
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 40934.0329443 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_{18}$ (as 18T1):

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

Intermediate fields

\(\Q(\sqrt{-35}) \), \(\Q(\zeta_{9})^+\), 6.0.281302875.3, \(\Q(\zeta_{27})^+\)

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

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 R R ${\href{/LocalNumberField/11.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/13.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/17.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/19.6.0.1}{6} }^{3}$ $18$ ${\href{/LocalNumberField/29.9.0.1}{9} }^{2}$ $18$ ${\href{/LocalNumberField/37.6.0.1}{6} }^{3}$ $18$ $18$ ${\href{/LocalNumberField/47.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/53.2.0.1}{2} }^{9}$ $18$

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
$3$3.9.22.8$x^{9} + 18 x^{7} + 24 x^{6} + 18 x^{5} + 18 x^{3} + 3$$9$$1$$22$$C_9$$[2, 3]$
3.9.22.8$x^{9} + 18 x^{7} + 24 x^{6} + 18 x^{5} + 18 x^{3} + 3$$9$$1$$22$$C_9$$[2, 3]$
5Data not computed
7Data not computed