Properties

Label 18.0.75855608471...6739.2
Degree $18$
Signature $[0, 9]$
Discriminant $-\,7^{12}\cdot 19^{17}$
Root discriminant $59.04$
Ramified primes $7, 19$
Class number $81$ (GRH)
Class group $[3, 3, 3, 3]$ (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![116851, 316197, 421421, 256689, 80200, -11572, 10679, -52973, 13605, -10185, 5739, -818, 476, -39, 39, -39, 1, -1, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - x^17 + x^16 - 39*x^15 + 39*x^14 - 39*x^13 + 476*x^12 - 818*x^11 + 5739*x^10 - 10185*x^9 + 13605*x^8 - 52973*x^7 + 10679*x^6 - 11572*x^5 + 80200*x^4 + 256689*x^3 + 421421*x^2 + 316197*x + 116851)
 
gp: K = bnfinit(x^18 - x^17 + x^16 - 39*x^15 + 39*x^14 - 39*x^13 + 476*x^12 - 818*x^11 + 5739*x^10 - 10185*x^9 + 13605*x^8 - 52973*x^7 + 10679*x^6 - 11572*x^5 + 80200*x^4 + 256689*x^3 + 421421*x^2 + 316197*x + 116851, 1)
 

Normalized defining polynomial

\( x^{18} - x^{17} + x^{16} - 39 x^{15} + 39 x^{14} - 39 x^{13} + 476 x^{12} - 818 x^{11} + 5739 x^{10} - 10185 x^{9} + 13605 x^{8} - 52973 x^{7} + 10679 x^{6} - 11572 x^{5} + 80200 x^{4} + 256689 x^{3} + 421421 x^{2} + 316197 x + 116851 \)

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:  \(-75855608471185389708554302866739=-\,7^{12}\cdot 19^{17}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $59.04$
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:  $7, 19$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(133=7\cdot 19\)
Dirichlet character group:    $\lbrace$$\chi_{133}(64,·)$, $\chi_{133}(1,·)$, $\chi_{133}(130,·)$, $\chi_{133}(8,·)$, $\chi_{133}(9,·)$, $\chi_{133}(74,·)$, $\chi_{133}(81,·)$, $\chi_{133}(86,·)$, $\chi_{133}(23,·)$, $\chi_{133}(106,·)$, $\chi_{133}(44,·)$, $\chi_{133}(109,·)$, $\chi_{133}(113,·)$, $\chi_{133}(50,·)$, $\chi_{133}(51,·)$, $\chi_{133}(116,·)$, $\chi_{133}(72,·)$, $\chi_{133}(60,·)$$\rbrace$
This is a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $\frac{1}{7} a^{15} + \frac{3}{7} a^{14} + \frac{3}{7} a^{13} - \frac{2}{7} a^{12} - \frac{2}{7} a^{11} - \frac{2}{7} a^{10} + \frac{2}{7} a^{8} + \frac{2}{7} a^{7} + \frac{2}{7} a^{6} - \frac{3}{7} a^{5} - \frac{3}{7} a^{4} - \frac{1}{7} a^{3}$, $\frac{1}{7763} a^{16} + \frac{214}{7763} a^{15} - \frac{687}{7763} a^{14} - \frac{2638}{7763} a^{13} - \frac{3385}{7763} a^{12} + \frac{185}{7763} a^{11} - \frac{3803}{7763} a^{10} - \frac{2259}{7763} a^{9} - \frac{297}{7763} a^{8} + \frac{2965}{7763} a^{7} + \frac{3576}{7763} a^{6} + \frac{2969}{7763} a^{5} + \frac{2530}{7763} a^{4} - \frac{2451}{7763} a^{3} + \frac{378}{1109} a^{2} + \frac{261}{1109} a - \frac{18}{1109}$, $\frac{1}{1006471927455797471152731670797337761578552639} a^{17} + \frac{25147584665119662691274443508255158985110}{1006471927455797471152731670797337761578552639} a^{16} - \frac{47058711495313395615826652757440301359341831}{1006471927455797471152731670797337761578552639} a^{15} - \frac{304988773523617002539972625444490447152761576}{1006471927455797471152731670797337761578552639} a^{14} + \frac{165940421262753828794737398779234497286652753}{1006471927455797471152731670797337761578552639} a^{13} - \frac{161804524106540399209107742394334102513790703}{1006471927455797471152731670797337761578552639} a^{12} - \frac{50758637040752966505194359971931342079225807}{143781703922256781593247381542476823082650377} a^{11} - \frac{206581344077976027651371496353862788745067040}{1006471927455797471152731670797337761578552639} a^{10} - \frac{27108251771115371337368381406476486619900551}{1006471927455797471152731670797337761578552639} a^{9} + \frac{376244712728795691511873265398267476575776078}{1006471927455797471152731670797337761578552639} a^{8} - \frac{73566479163088264792774123257229822659350658}{1006471927455797471152731670797337761578552639} a^{7} - \frac{23654871270223996343881748193382698171506306}{1006471927455797471152731670797337761578552639} a^{6} - \frac{93773022326736400731107924015614477931541360}{1006471927455797471152731670797337761578552639} a^{5} - \frac{45568910712456393152301453514622610903365277}{143781703922256781593247381542476823082650377} a^{4} - \frac{49434874096517183223346613061828487474196356}{143781703922256781593247381542476823082650377} a^{3} - \frac{14647651863820053196395938724712422466004695}{143781703922256781593247381542476823082650377} a^{2} - \frac{60733681959399806165204200212885510985737178}{143781703922256781593247381542476823082650377} a + \frac{61365233334818979143861255956650773046612790}{143781703922256781593247381542476823082650377}$

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

Class group and class number

$C_{3}\times C_{3}\times C_{3}\times C_{3}$, which has order $81$ (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:  \( 4369063.34801 \) (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

\(\Q(\sqrt{-19}) \), 3.3.361.1, 6.0.2476099.1, 9.9.1998099208210609.2

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 $18$ $18$ ${\href{/LocalNumberField/5.9.0.1}{9} }^{2}$ R ${\href{/LocalNumberField/11.3.0.1}{3} }^{6}$ $18$ ${\href{/LocalNumberField/17.9.0.1}{9} }^{2}$ R ${\href{/LocalNumberField/23.9.0.1}{9} }^{2}$ $18$ ${\href{/LocalNumberField/31.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/37.6.0.1}{6} }^{3}$ $18$ ${\href{/LocalNumberField/43.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/47.9.0.1}{9} }^{2}$ $18$ $18$

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
$7$7.3.2.1$x^{3} + 14$$3$$1$$2$$C_3$$[\ ]_{3}$
7.3.2.1$x^{3} + 14$$3$$1$$2$$C_3$$[\ ]_{3}$
7.3.2.1$x^{3} + 14$$3$$1$$2$$C_3$$[\ ]_{3}$
7.3.2.1$x^{3} + 14$$3$$1$$2$$C_3$$[\ ]_{3}$
7.3.2.1$x^{3} + 14$$3$$1$$2$$C_3$$[\ ]_{3}$
7.3.2.1$x^{3} + 14$$3$$1$$2$$C_3$$[\ ]_{3}$
19Data not computed