Properties

Label 18.0.31777345526...1299.2
Degree $18$
Signature $[0, 9]$
Discriminant $-\,3^{44}\cdot 19^{9}$
Root discriminant $63.93$
Ramified primes $3, 19$
Class number $7492$ (GRH)
Class group $[2, 3746]$ (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![28658393, -21799593, 30278943, -19032684, 15278400, -8116569, 4844985, -2200338, 1056267, -411866, 164196, -54630, 18192, -5040, 1368, -300, 63, -9, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 9*x^17 + 63*x^16 - 300*x^15 + 1368*x^14 - 5040*x^13 + 18192*x^12 - 54630*x^11 + 164196*x^10 - 411866*x^9 + 1056267*x^8 - 2200338*x^7 + 4844985*x^6 - 8116569*x^5 + 15278400*x^4 - 19032684*x^3 + 30278943*x^2 - 21799593*x + 28658393)
 
gp: K = bnfinit(x^18 - 9*x^17 + 63*x^16 - 300*x^15 + 1368*x^14 - 5040*x^13 + 18192*x^12 - 54630*x^11 + 164196*x^10 - 411866*x^9 + 1056267*x^8 - 2200338*x^7 + 4844985*x^6 - 8116569*x^5 + 15278400*x^4 - 19032684*x^3 + 30278943*x^2 - 21799593*x + 28658393, 1)
 

Normalized defining polynomial

\( x^{18} - 9 x^{17} + 63 x^{16} - 300 x^{15} + 1368 x^{14} - 5040 x^{13} + 18192 x^{12} - 54630 x^{11} + 164196 x^{10} - 411866 x^{9} + 1056267 x^{8} - 2200338 x^{7} + 4844985 x^{6} - 8116569 x^{5} + 15278400 x^{4} - 19032684 x^{3} + 30278943 x^{2} - 21799593 x + 28658393 \)

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:  \(-317773455265378312682733715471299=-\,3^{44}\cdot 19^{9}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $63.93$
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:  $3, 19$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(513=3^{3}\cdot 19\)
Dirichlet character group:    $\lbrace$$\chi_{513}(1,·)$, $\chi_{513}(322,·)$, $\chi_{513}(265,·)$, $\chi_{513}(343,·)$, $\chi_{513}(400,·)$, $\chi_{513}(151,·)$, $\chi_{513}(94,·)$, $\chi_{513}(229,·)$, $\chi_{513}(208,·)$, $\chi_{513}(37,·)$, $\chi_{513}(172,·)$, $\chi_{513}(493,·)$, $\chi_{513}(115,·)$, $\chi_{513}(436,·)$, $\chi_{513}(286,·)$, $\chi_{513}(457,·)$, $\chi_{513}(58,·)$, $\chi_{513}(379,·)$$\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}{12440870317958056479097007757878329477720025547457} a^{17} - \frac{1937003492585187251396144797716488230758304787094}{12440870317958056479097007757878329477720025547457} a^{16} + \frac{3071201333118363804279824776341312267414834301228}{12440870317958056479097007757878329477720025547457} a^{15} - \frac{5436789091039797883005870576779988239423234150999}{12440870317958056479097007757878329477720025547457} a^{14} + \frac{4688620761565292111559679548976014643365832882068}{12440870317958056479097007757878329477720025547457} a^{13} - \frac{4426432798127403288064430287458856922376629965000}{12440870317958056479097007757878329477720025547457} a^{12} + \frac{5605351058966048807269613032255501889754283899099}{12440870317958056479097007757878329477720025547457} a^{11} - \frac{5427800159024562851307030800916274084412569601642}{12440870317958056479097007757878329477720025547457} a^{10} - \frac{4704387881728437074195030618007271765267447957674}{12440870317958056479097007757878329477720025547457} a^{9} - \frac{5580290417238958473076632401562818223747885372145}{12440870317958056479097007757878329477720025547457} a^{8} - \frac{2920241800497606644075829256679935042547648124424}{12440870317958056479097007757878329477720025547457} a^{7} - \frac{1127510100111857455114421359823379807433365637936}{12440870317958056479097007757878329477720025547457} a^{6} - \frac{5808636448350361662156625053648864331180539372835}{12440870317958056479097007757878329477720025547457} a^{5} - \frac{4757632188556443488921656267155023445572648265609}{12440870317958056479097007757878329477720025547457} a^{4} + \frac{3456745603328810046436977984933852058291309332809}{12440870317958056479097007757878329477720025547457} a^{3} + \frac{2326176202463518013802375672494452892413685963293}{12440870317958056479097007757878329477720025547457} a^{2} + \frac{2706091179963956547489512282289278619165442056714}{12440870317958056479097007757878329477720025547457} a - \frac{5736577488520219750784576244421760849024391517121}{12440870317958056479097007757878329477720025547457}$

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

Class group and class number

$C_{2}\times C_{3746}$, which has order $7492$ (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

\(\Q(\sqrt{-19}) \), \(\Q(\zeta_{9})^+\), 6.0.45001899.1, \(\Q(\zeta_{27})^+\)

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 ${\href{/LocalNumberField/5.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/7.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/11.9.0.1}{9} }^{2}$ $18$ ${\href{/LocalNumberField/17.3.0.1}{3} }^{6}$ R ${\href{/LocalNumberField/23.9.0.1}{9} }^{2}$ $18$ $18$ ${\href{/LocalNumberField/37.6.0.1}{6} }^{3}$ $18$ ${\href{/LocalNumberField/43.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/47.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/53.2.0.1}{2} }^{9}$ $18$

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
3Data not computed
$19$19.6.3.2$x^{6} - 361 x^{2} + 27436$$2$$3$$3$$C_6$$[\ ]_{2}^{3}$
19.6.3.2$x^{6} - 361 x^{2} + 27436$$2$$3$$3$$C_6$$[\ ]_{2}^{3}$
19.6.3.2$x^{6} - 361 x^{2} + 27436$$2$$3$$3$$C_6$$[\ ]_{2}^{3}$