Properties

Label 18.18.2409670295...3125.1
Degree $18$
Signature $[18, 0]$
Discriminant $5^{9}\cdot 37^{16}$
Root discriminant $55.39$
Ramified primes $5, 37$
Class number $1$ (GRH)
Class group Trivial (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![-31, -565, -1984, 4861, 24080, -10039, -56437, 21175, 52436, -25476, -19596, 12069, 2827, -2523, -39, 230, -21, -7, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 7*x^17 - 21*x^16 + 230*x^15 - 39*x^14 - 2523*x^13 + 2827*x^12 + 12069*x^11 - 19596*x^10 - 25476*x^9 + 52436*x^8 + 21175*x^7 - 56437*x^6 - 10039*x^5 + 24080*x^4 + 4861*x^3 - 1984*x^2 - 565*x - 31)
 
gp: K = bnfinit(x^18 - 7*x^17 - 21*x^16 + 230*x^15 - 39*x^14 - 2523*x^13 + 2827*x^12 + 12069*x^11 - 19596*x^10 - 25476*x^9 + 52436*x^8 + 21175*x^7 - 56437*x^6 - 10039*x^5 + 24080*x^4 + 4861*x^3 - 1984*x^2 - 565*x - 31, 1)
 

Normalized defining polynomial

\( x^{18} - 7 x^{17} - 21 x^{16} + 230 x^{15} - 39 x^{14} - 2523 x^{13} + 2827 x^{12} + 12069 x^{11} - 19596 x^{10} - 25476 x^{9} + 52436 x^{8} + 21175 x^{7} - 56437 x^{6} - 10039 x^{5} + 24080 x^{4} + 4861 x^{3} - 1984 x^{2} - 565 x - 31 \)

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:  \(24096702957455403051316876953125=5^{9}\cdot 37^{16}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $55.39$
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:  $5, 37$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(185=5\cdot 37\)
Dirichlet character group:    $\lbrace$$\chi_{185}(1,·)$, $\chi_{185}(71,·)$, $\chi_{185}(9,·)$, $\chi_{185}(144,·)$, $\chi_{185}(81,·)$, $\chi_{185}(84,·)$, $\chi_{185}(174,·)$, $\chi_{185}(86,·)$, $\chi_{185}(26,·)$, $\chi_{185}(16,·)$, $\chi_{185}(34,·)$, $\chi_{185}(164,·)$, $\chi_{185}(44,·)$, $\chi_{185}(46,·)$, $\chi_{185}(49,·)$, $\chi_{185}(181,·)$, $\chi_{185}(121,·)$, $\chi_{185}(149,·)$$\rbrace$
This is not a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $\frac{1}{31} a^{15} + \frac{13}{31} a^{14} + \frac{12}{31} a^{13} - \frac{10}{31} a^{12} - \frac{11}{31} a^{11} + \frac{8}{31} a^{10} - \frac{6}{31} a^{9} + \frac{2}{31} a^{8} - \frac{7}{31} a^{7} - \frac{7}{31} a^{6} - \frac{11}{31} a^{5} + \frac{8}{31} a^{4} + \frac{6}{31} a^{3} - \frac{11}{31} a^{2} + \frac{13}{31} a$, $\frac{1}{1333} a^{16} + \frac{11}{1333} a^{15} - \frac{107}{1333} a^{14} + \frac{555}{1333} a^{13} - \frac{425}{1333} a^{12} - \frac{652}{1333} a^{11} - \frac{611}{1333} a^{10} + \frac{479}{1333} a^{9} + \frac{268}{1333} a^{8} + \frac{348}{1333} a^{7} + \frac{3}{1333} a^{6} - \frac{590}{1333} a^{5} - \frac{227}{1333} a^{4} - \frac{333}{1333} a^{3} + \frac{252}{1333} a^{2} + \frac{253}{1333} a - \frac{5}{43}$, $\frac{1}{172299010580371339307} a^{17} + \frac{6573078984395758}{172299010580371339307} a^{16} - \frac{2723752179336767600}{172299010580371339307} a^{15} + \frac{3133086374563131394}{172299010580371339307} a^{14} + \frac{79348700309983218247}{172299010580371339307} a^{13} + \frac{61955208774448455651}{172299010580371339307} a^{12} + \frac{62137731596639599683}{172299010580371339307} a^{11} - \frac{40919747140837764227}{172299010580371339307} a^{10} + \frac{43364931567961704814}{172299010580371339307} a^{9} + \frac{1023019638921373524}{4006953734427240449} a^{8} - \frac{77953124837792168978}{172299010580371339307} a^{7} + \frac{10134127444845417560}{172299010580371339307} a^{6} - \frac{52770295421201019494}{172299010580371339307} a^{5} - \frac{31772977212411374714}{172299010580371339307} a^{4} - \frac{24631431209204360366}{172299010580371339307} a^{3} - \frac{11004992178911770158}{172299010580371339307} a^{2} + \frac{6937517732456204277}{172299010580371339307} a - \frac{1870339387661925986}{5558032599366817397}$

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:  \( 8441875446.42 \) (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

\(\Q(\sqrt{5}) \), 3.3.1369.1, 6.6.234270125.1, 9.9.3512479453921.1

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 $18$ $18$ R $18$ ${\href{/LocalNumberField/11.3.0.1}{3} }^{6}$ $18$ $18$ ${\href{/LocalNumberField/19.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/23.6.0.1}{6} }^{3}$ ${\href{/LocalNumberField/29.3.0.1}{3} }^{6}$ ${\href{/LocalNumberField/31.1.0.1}{1} }^{18}$ R ${\href{/LocalNumberField/41.9.0.1}{9} }^{2}$ ${\href{/LocalNumberField/43.2.0.1}{2} }^{9}$ ${\href{/LocalNumberField/47.6.0.1}{6} }^{3}$ $18$ ${\href{/LocalNumberField/59.9.0.1}{9} }^{2}$

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
5Data not computed
37Data not computed