Properties

Label 18.0.80183998266...3872.2
Degree $18$
Signature $[0, 9]$
Discriminant $-\,2^{18}\cdot 13^{9}\cdot 19^{16}$
Root discriminant $98.78$
Ramified primes $2, 13, 19$
Class number $797202$ (GRH)
Class group $[9, 88578]$ (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![34608450449, -4071582408, 16612972693, -1771316602, 3749466651, -358900172, 521749394, -44214104, 49341285, -3626002, 3292921, -203272, 155495, -7646, 5032, -178, 102, -2, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 2*x^17 + 102*x^16 - 178*x^15 + 5032*x^14 - 7646*x^13 + 155495*x^12 - 203272*x^11 + 3292921*x^10 - 3626002*x^9 + 49341285*x^8 - 44214104*x^7 + 521749394*x^6 - 358900172*x^5 + 3749466651*x^4 - 1771316602*x^3 + 16612972693*x^2 - 4071582408*x + 34608450449)
 
gp: K = bnfinit(x^18 - 2*x^17 + 102*x^16 - 178*x^15 + 5032*x^14 - 7646*x^13 + 155495*x^12 - 203272*x^11 + 3292921*x^10 - 3626002*x^9 + 49341285*x^8 - 44214104*x^7 + 521749394*x^6 - 358900172*x^5 + 3749466651*x^4 - 1771316602*x^3 + 16612972693*x^2 - 4071582408*x + 34608450449, 1)
 

Normalized defining polynomial

\( x^{18} - 2 x^{17} + 102 x^{16} - 178 x^{15} + 5032 x^{14} - 7646 x^{13} + 155495 x^{12} - 203272 x^{11} + 3292921 x^{10} - 3626002 x^{9} + 49341285 x^{8} - 44214104 x^{7} + 521749394 x^{6} - 358900172 x^{5} + 3749466651 x^{4} - 1771316602 x^{3} + 16612972693 x^{2} - 4071582408 x + 34608450449 \)

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:  \(-801839982660831770253640955071823872=-\,2^{18}\cdot 13^{9}\cdot 19^{16}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $98.78$
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:  $2, 13, 19$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(988=2^{2}\cdot 13\cdot 19\)
Dirichlet character group:    $\lbrace$$\chi_{988}(1,·)$, $\chi_{988}(519,·)$, $\chi_{988}(207,·)$, $\chi_{988}(467,·)$, $\chi_{988}(727,·)$, $\chi_{988}(729,·)$, $\chi_{988}(157,·)$, $\chi_{988}(415,·)$, $\chi_{988}(935,·)$, $\chi_{988}(937,·)$, $\chi_{988}(365,·)$, $\chi_{988}(625,·)$, $\chi_{988}(883,·)$, $\chi_{988}(885,·)$, $\chi_{988}(311,·)$, $\chi_{988}(313,·)$, $\chi_{988}(571,·)$, $\chi_{988}(833,·)$$\rbrace$
This is a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $a^{16}$, $\frac{1}{899305918516152974213000422394094414327875617334558656169637401} a^{17} - \frac{57985419662963667466090220414650834868902689274754845457564892}{899305918516152974213000422394094414327875617334558656169637401} a^{16} - \frac{91467323654105673614643154865459018178024653977203039866564236}{899305918516152974213000422394094414327875617334558656169637401} a^{15} - \frac{248611827103197624134122583861450655732798154162940956925043508}{899305918516152974213000422394094414327875617334558656169637401} a^{14} + \frac{142247151921000435815892152315875056029348339367278505906540415}{899305918516152974213000422394094414327875617334558656169637401} a^{13} + \frac{78749583607847570754771257394660753687478582545029807100109705}{899305918516152974213000422394094414327875617334558656169637401} a^{12} - \frac{413417231788056587570940633184890942896352362239948763626163263}{899305918516152974213000422394094414327875617334558656169637401} a^{11} + \frac{276285562075172351149660099891520842053239796281947619970318408}{899305918516152974213000422394094414327875617334558656169637401} a^{10} + \frac{49938563482478291216308306816091215563722830085118229884466978}{899305918516152974213000422394094414327875617334558656169637401} a^{9} - \frac{271143171583567584063760330898463438158249363510921900134188730}{899305918516152974213000422394094414327875617334558656169637401} a^{8} - \frac{28835588012819625722359020483002783922447155668497662679306808}{899305918516152974213000422394094414327875617334558656169637401} a^{7} - \frac{164644020481774620014977936710291759466422149740762692190857241}{899305918516152974213000422394094414327875617334558656169637401} a^{6} + \frac{332635871989595163751656206191735287038299027735843771362331793}{899305918516152974213000422394094414327875617334558656169637401} a^{5} + \frac{119331080990966300424645085324259785261574810593187472032755058}{899305918516152974213000422394094414327875617334558656169637401} a^{4} + \frac{447467670595758576261290963474757366896237669600791075834556305}{899305918516152974213000422394094414327875617334558656169637401} a^{3} + \frac{163720293362115353934220268184886814667235116708105481427794829}{899305918516152974213000422394094414327875617334558656169637401} a^{2} + \frac{432306278197085076761863738486707141751886810648179617494581131}{899305918516152974213000422394094414327875617334558656169637401} a - \frac{356080768135620923261924881584276378883409914091327669355396708}{899305918516152974213000422394094414327875617334558656169637401}$

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

Class group and class number

$C_{9}\times C_{88578}$, which has order $797202$ (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:  \( 22305.8950792 \) (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

\(\Q(\sqrt{-13}) \), 3.3.361.1, 6.0.18324175168.4, \(\Q(\zeta_{19})^+\)

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 R $18$ $18$ ${\href{/LocalNumberField/7.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/11.3.0.1}{3} }^{6}$ R ${\href{/LocalNumberField/17.9.0.1}{9} }^{2}$ R $18$ ${\href{/LocalNumberField/29.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/31.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/37.2.0.1}{2} }^{9}$ $18$ $18$ ${\href{/LocalNumberField/47.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/53.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/59.9.0.1}{9} }^{2}$

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
2Data not computed
13Data not computed
$19$19.9.8.8$x^{9} - 19$$9$$1$$8$$C_9$$[\ ]_{9}$
19.9.8.8$x^{9} - 19$$9$$1$$8$$C_9$$[\ ]_{9}$