Properties

Label 18.0.103...863.1
Degree $18$
Signature $[0, 9]$
Discriminant $-1.038\times 10^{19}$
Root discriminant \(11.39\)
Ramified primes $7,23$
Class number $1$
Class group trivial
Galois group $C_9:C_6$ (as 18T18)

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Show commands: Magma / Oscar / PariGP / SageMath

Normalized defining polynomial

sage: x = polygen(QQ); K.<a> = NumberField(x^18 - 4*x^17 + 11*x^16 - 22*x^15 + 36*x^14 - 53*x^13 + 80*x^12 - 116*x^11 + 154*x^10 - 173*x^9 + 154*x^8 - 116*x^7 + 80*x^6 - 53*x^5 + 36*x^4 - 22*x^3 + 11*x^2 - 4*x + 1)
 
gp: K = bnfinit(y^18 - 4*y^17 + 11*y^16 - 22*y^15 + 36*y^14 - 53*y^13 + 80*y^12 - 116*y^11 + 154*y^10 - 173*y^9 + 154*y^8 - 116*y^7 + 80*y^6 - 53*y^5 + 36*y^4 - 22*y^3 + 11*y^2 - 4*y + 1, 1)
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(x^18 - 4*x^17 + 11*x^16 - 22*x^15 + 36*x^14 - 53*x^13 + 80*x^12 - 116*x^11 + 154*x^10 - 173*x^9 + 154*x^8 - 116*x^7 + 80*x^6 - 53*x^5 + 36*x^4 - 22*x^3 + 11*x^2 - 4*x + 1);
 
oscar: Qx, x = PolynomialRing(QQ); K, a = NumberField(x^18 - 4*x^17 + 11*x^16 - 22*x^15 + 36*x^14 - 53*x^13 + 80*x^12 - 116*x^11 + 154*x^10 - 173*x^9 + 154*x^8 - 116*x^7 + 80*x^6 - 53*x^5 + 36*x^4 - 22*x^3 + 11*x^2 - 4*x + 1)
 

\( x^{18} - 4 x^{17} + 11 x^{16} - 22 x^{15} + 36 x^{14} - 53 x^{13} + 80 x^{12} - 116 x^{11} + 154 x^{10} + \cdots + 1 \) Copy content Toggle raw display

sage: K.defining_polynomial()
 
gp: K.pol
 
magma: DefiningPolynomial(K);
 
oscar: defining_polynomial(K)
 

Invariants

Degree:  $18$
sage: K.degree()
 
gp: poldegree(K.pol)
 
magma: Degree(K);
 
oscar: degree(K)
 
Signature:  $[0, 9]$
sage: K.signature()
 
gp: K.sign
 
magma: Signature(K);
 
oscar: signature(K)
 
Discriminant:   \(-10383286663954563863\) \(\medspace = -\,7^{8}\cdot 23^{9}\) Copy content Toggle raw display
sage: K.disc()
 
gp: K.disc
 
magma: OK := Integers(K); Discriminant(OK);
 
oscar: OK = ring_of_integers(K); discriminant(OK)
 
Root discriminant:  \(11.39\)
sage: (K.disc().abs())^(1./K.degree())
 
gp: abs(K.disc)^(1/poldegree(K.pol))
 
magma: Abs(Discriminant(OK))^(1/Degree(K));
 
oscar: (1.0 * dK)^(1/degree(K))
 
Galois root discriminant:  $7^{2/3}23^{1/2}\approx 17.5494136775664$
Ramified primes:   \(7\), \(23\) Copy content Toggle raw display
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
magma: PrimeDivisors(Discriminant(OK));
 
oscar: prime_divisors(discriminant((OK)))
 
Discriminant root field:  \(\Q(\sqrt{-23}) \)
$\card{ \Aut(K/\Q) }$:  $6$
sage: K.automorphisms()
 
magma: Automorphisms(K);
 
oscar: automorphisms(K)
 
This field is not Galois over $\Q$.
This is not a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $\frac{1}{1597}a^{16}+\frac{210}{1597}a^{15}+\frac{234}{1597}a^{14}+\frac{337}{1597}a^{13}+\frac{55}{1597}a^{12}+\frac{201}{1597}a^{11}-\frac{80}{1597}a^{10}+\frac{130}{1597}a^{9}-\frac{692}{1597}a^{8}+\frac{130}{1597}a^{7}-\frac{80}{1597}a^{6}+\frac{201}{1597}a^{5}+\frac{55}{1597}a^{4}+\frac{337}{1597}a^{3}+\frac{234}{1597}a^{2}+\frac{210}{1597}a+\frac{1}{1597}$, $\frac{1}{11179}a^{17}+\frac{2}{11179}a^{16}-\frac{327}{11179}a^{15}+\frac{2769}{11179}a^{14}+\frac{1824}{11179}a^{13}+\frac{4731}{11179}a^{12}-\frac{1963}{11179}a^{11}-\frac{3991}{11179}a^{10}+\frac{4208}{11179}a^{9}+\frac{1933}{11179}a^{8}-\frac{3165}{11179}a^{7}+\frac{2468}{11179}a^{6}-\frac{1828}{11179}a^{5}-\frac{3118}{11179}a^{4}-\frac{4385}{11179}a^{3}+\frac{1045}{11179}a^{2}+\frac{2634}{11179}a-\frac{1805}{11179}$ Copy content Toggle raw display

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

Monogenic:  Not computed
Index:  $1$
Inessential primes:  None

Class group and class number

Trivial group, which has order $1$

sage: K.class_group().invariants()
 
gp: K.clgp
 
magma: ClassGroup(K);
 
oscar: class_group(K)
 

Unit group

sage: UK = K.unit_group()
 
magma: UK, fUK := UnitGroup(K);
 
oscar: UK, fUK = unit_group(OK)
 
Rank:  $8$
sage: UK.rank()
 
gp: K.fu
 
magma: UnitRank(K);
 
oscar: rank(UK)
 
Torsion generator:   \( -1 \)  (order $2$) Copy content Toggle raw display
sage: UK.torsion_generator()
 
gp: K.tu[2]
 
magma: K!f(TU.1) where TU,f is TorsionUnitGroup(K);
 
oscar: torsion_units_generator(OK)
 
Fundamental units:   $\frac{5140}{11179}a^{17}-\frac{22942}{11179}a^{16}+\frac{62220}{11179}a^{15}-\frac{125719}{11179}a^{14}+\frac{202945}{11179}a^{13}-\frac{292672}{11179}a^{12}+\frac{437039}{11179}a^{11}-\frac{640320}{11179}a^{10}+\frac{843593}{11179}a^{9}-\frac{935947}{11179}a^{8}+\frac{798467}{11179}a^{7}-\frac{530900}{11179}a^{6}+\frac{348409}{11179}a^{5}-\frac{213268}{11179}a^{4}+\frac{137656}{11179}a^{3}-\frac{99774}{11179}a^{2}+\frac{33604}{11179}a-\frac{9994}{11179}$, $\frac{5956}{11179}a^{17}-\frac{19203}{11179}a^{16}+\frac{47815}{11179}a^{15}-\frac{78495}{11179}a^{14}+\frac{109693}{11179}a^{13}-\frac{139509}{11179}a^{12}+\frac{220132}{11179}a^{11}-\frac{309392}{11179}a^{10}+\frac{370285}{11179}a^{9}-\frac{280071}{11179}a^{8}+\frac{77155}{11179}a^{7}+\frac{62380}{11179}a^{6}-\frac{60171}{11179}a^{5}-\frac{3427}{11179}a^{4}-\frac{13948}{11179}a^{3}+\frac{38652}{11179}a^{2}-\frac{24005}{11179}a+\frac{17219}{11179}$, $\frac{1478}{11179}a^{17}-\frac{11380}{11179}a^{16}+\frac{27519}{11179}a^{15}-\frac{55751}{11179}a^{14}+\frac{78082}{11179}a^{13}-\frac{101018}{11179}a^{12}+\frac{142020}{11179}a^{11}-\frac{235502}{11179}a^{10}+\frac{286588}{11179}a^{9}-\frac{279586}{11179}a^{8}+\frac{132313}{11179}a^{7}+\frac{32330}{11179}a^{6}-\frac{16178}{11179}a^{5}-\frac{30964}{11179}a^{4}+\frac{23244}{11179}a^{3}+\frac{884}{11179}a^{2}-\frac{23007}{11179}a+\frac{12013}{11179}$, $\frac{2878}{11179}a^{17}-\frac{11436}{11179}a^{16}+\frac{43143}{11179}a^{15}-\frac{100544}{11179}a^{14}+\frac{193582}{11179}a^{13}-\frac{308561}{11179}a^{12}+\frac{452939}{11179}a^{11}-\frac{642125}{11179}a^{10}+\frac{932464}{11179}a^{9}-\frac{1186534}{11179}a^{8}+\frac{1266082}{11179}a^{7}-\frac{1090960}{11179}a^{6}+\frac{662605}{11179}a^{5}-\frac{405835}{11179}a^{4}+\frac{311091}{11179}a^{3}-\frac{199351}{11179}a^{2}+\frac{113577}{11179}a-\frac{36105}{11179}$, $\frac{27714}{11179}a^{17}-\frac{96423}{11179}a^{16}+\frac{243427}{11179}a^{15}-\frac{446022}{11179}a^{14}+\frac{673313}{11179}a^{13}-\frac{954864}{11179}a^{12}+\frac{1477858}{11179}a^{11}-\frac{2106693}{11179}a^{10}+\frac{2640912}{11179}a^{9}-\frac{2672095}{11179}a^{8}+\frac{1953433}{11179}a^{7}-\frac{1306406}{11179}a^{6}+\frac{937691}{11179}a^{5}-\frac{603340}{11179}a^{4}+\frac{407138}{11179}a^{3}-\frac{211153}{11179}a^{2}+\frac{71857}{11179}a-\frac{26627}{11179}$, $\frac{6873}{11179}a^{17}-\frac{26588}{11179}a^{16}+\frac{81303}{11179}a^{15}-\frac{166086}{11179}a^{14}+\frac{285274}{11179}a^{13}-\frac{422099}{11179}a^{12}+\frac{625019}{11179}a^{11}-\frac{895208}{11179}a^{10}+\frac{1241911}{11179}a^{9}-\frac{1428890}{11179}a^{8}+\frac{1331121}{11179}a^{7}-\frac{994921}{11179}a^{6}+\frac{580301}{11179}a^{5}-\frac{407243}{11179}a^{4}+\frac{325776}{11179}a^{3}-\frac{187756}{11179}a^{2}+\frac{97655}{11179}a-\frac{26230}{11179}$, $\frac{6815}{11179}a^{17}-\frac{15945}{11179}a^{16}+\frac{34427}{11179}a^{15}-\frac{44882}{11179}a^{14}+\frac{49121}{11179}a^{13}-\frac{60036}{11179}a^{12}+\frac{117861}{11179}a^{11}-\frac{138254}{11179}a^{10}+\frac{116001}{11179}a^{9}+\frac{12863}{11179}a^{8}-\frac{183222}{11179}a^{7}+\frac{136404}{11179}a^{6}-\frac{57656}{11179}a^{5}+\frac{29976}{11179}a^{4}-\frac{19773}{11179}a^{3}+\frac{55798}{11179}a^{2}-\frac{31527}{11179}a+\frac{10966}{11179}$, $\frac{8937}{11179}a^{17}-\frac{34570}{11179}a^{16}+\frac{82827}{11179}a^{15}-\frac{146434}{11179}a^{14}+\frac{203699}{11179}a^{13}-\frac{266565}{11179}a^{12}+\frac{410696}{11179}a^{11}-\frac{606828}{11179}a^{10}+\frac{717666}{11179}a^{9}-\frac{618144}{11179}a^{8}+\frac{255852}{11179}a^{7}+\frac{26102}{11179}a^{6}+\frac{7415}{11179}a^{5}-\frac{52452}{11179}a^{4}+\frac{16379}{11179}a^{3}+\frac{29704}{11179}a^{2}-\frac{38378}{11179}a+\frac{25821}{11179}$ Copy content Toggle raw display
sage: UK.fundamental_units()
 
gp: K.fu
 
magma: [K|fUK(g): g in Generators(UK)];
 
oscar: [K(fUK(a)) for a in gens(UK)]
 
Regulator:  \( 77.8161636269 \)
sage: K.regulator()
 
gp: K.reg
 
magma: Regulator(K);
 
oscar: regulator(K)
 

Class number formula

\[ \begin{aligned}\lim_{s\to 1} (s-1)\zeta_K(s) =\mathstrut & \frac{2^{r_1}\cdot (2\pi)^{r_2}\cdot R\cdot h}{w\cdot\sqrt{|D|}}\cr \approx\mathstrut &\frac{2^{0}\cdot(2\pi)^{9}\cdot 77.8161636269 \cdot 1}{2\cdot\sqrt{10383286663954563863}}\cr\approx \mathstrut & 0.184285520456 \end{aligned}\]

# self-contained SageMath code snippet to compute the analytic class number formula
 
x = polygen(QQ); K.<a> = NumberField(x^18 - 4*x^17 + 11*x^16 - 22*x^15 + 36*x^14 - 53*x^13 + 80*x^12 - 116*x^11 + 154*x^10 - 173*x^9 + 154*x^8 - 116*x^7 + 80*x^6 - 53*x^5 + 36*x^4 - 22*x^3 + 11*x^2 - 4*x + 1)
 
DK = K.disc(); r1,r2 = K.signature(); RK = K.regulator(); RR = RK.parent()
 
hK = K.class_number(); wK = K.unit_group().torsion_generator().order();
 
2^r1 * (2*RR(pi))^r2 * RK * hK / (wK * RR(sqrt(abs(DK))))
 
# self-contained Pari/GP code snippet to compute the analytic class number formula
 
K = bnfinit(x^18 - 4*x^17 + 11*x^16 - 22*x^15 + 36*x^14 - 53*x^13 + 80*x^12 - 116*x^11 + 154*x^10 - 173*x^9 + 154*x^8 - 116*x^7 + 80*x^6 - 53*x^5 + 36*x^4 - 22*x^3 + 11*x^2 - 4*x + 1, 1);
 
[polcoeff (lfunrootres (lfuncreate (K))[1][1][2], -1), 2^K.r1 * (2*Pi)^K.r2 * K.reg * K.no / (K.tu[1] * sqrt (abs (K.disc)))]
 
/* self-contained Magma code snippet to compute the analytic class number formula */
 
Qx<x> := PolynomialRing(QQ); K<a> := NumberField(x^18 - 4*x^17 + 11*x^16 - 22*x^15 + 36*x^14 - 53*x^13 + 80*x^12 - 116*x^11 + 154*x^10 - 173*x^9 + 154*x^8 - 116*x^7 + 80*x^6 - 53*x^5 + 36*x^4 - 22*x^3 + 11*x^2 - 4*x + 1);
 
OK := Integers(K); DK := Discriminant(OK);
 
UK, fUK := UnitGroup(OK); clK, fclK := ClassGroup(OK);
 
r1,r2 := Signature(K); RK := Regulator(K); RR := Parent(RK);
 
hK := #clK; wK := #TorsionSubgroup(UK);
 
2^r1 * (2*Pi(RR))^r2 * RK * hK / (wK * Sqrt(RR!Abs(DK)));
 
# self-contained Oscar code snippet to compute the analytic class number formula
 
Qx, x = PolynomialRing(QQ); K, a = NumberField(x^18 - 4*x^17 + 11*x^16 - 22*x^15 + 36*x^14 - 53*x^13 + 80*x^12 - 116*x^11 + 154*x^10 - 173*x^9 + 154*x^8 - 116*x^7 + 80*x^6 - 53*x^5 + 36*x^4 - 22*x^3 + 11*x^2 - 4*x + 1);
 
OK = ring_of_integers(K); DK = discriminant(OK);
 
UK, fUK = unit_group(OK); clK, fclK = class_group(OK);
 
r1,r2 = signature(K); RK = regulator(K); RR = parent(RK);
 
hK = order(clK); wK = torsion_units_order(K);
 
2^r1 * (2*pi)^r2 * RK * hK / (wK * sqrt(RR(abs(DK))))
 

Galois group

$C_9:C_6$ (as 18T18):

sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
magma: G = GaloisGroup(K);
 
oscar: G, Gtx = galois_group(K); G, transitive_group_identification(G)
 
A solvable group of order 54
The 10 conjugacy class representatives for $C_9:C_6$
Character table for $C_9:C_6$

Intermediate fields

\(\Q(\sqrt{-23}) \), 3.1.23.1 x3, 6.0.12167.1, 9.1.671898241.1 x3

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

sage: K.subfields()[1:-1]
 
gp: L = nfsubfields(K); L[2..length(b)]
 
magma: L := Subfields(K); L[2..#L];
 
oscar: subfields(K)[2:end-1]
 

Sibling fields

Degree 9 sibling: data not computed
Degree 27 sibling: data not computed
Minimal sibling: 9.1.671898241.1

Frobenius cycle types

$p$ $2$ $3$ $5$ $7$ $11$ $13$ $17$ $19$ $23$ $29$ $31$ $37$ $41$ $43$ $47$ $53$ $59$
Cycle type ${\href{/padicField/2.9.0.1}{9} }^{2}$ ${\href{/padicField/3.9.0.1}{9} }^{2}$ ${\href{/padicField/5.6.0.1}{6} }^{2}{,}\,{\href{/padicField/5.2.0.1}{2} }^{3}$ R ${\href{/padicField/11.6.0.1}{6} }^{2}{,}\,{\href{/padicField/11.2.0.1}{2} }^{3}$ ${\href{/padicField/13.9.0.1}{9} }^{2}$ ${\href{/padicField/17.6.0.1}{6} }^{2}{,}\,{\href{/padicField/17.2.0.1}{2} }^{3}$ ${\href{/padicField/19.6.0.1}{6} }^{2}{,}\,{\href{/padicField/19.2.0.1}{2} }^{3}$ R ${\href{/padicField/29.9.0.1}{9} }^{2}$ ${\href{/padicField/31.9.0.1}{9} }^{2}$ ${\href{/padicField/37.6.0.1}{6} }^{2}{,}\,{\href{/padicField/37.2.0.1}{2} }^{3}$ ${\href{/padicField/41.9.0.1}{9} }^{2}$ ${\href{/padicField/43.2.0.1}{2} }^{9}$ ${\href{/padicField/47.9.0.1}{9} }^{2}$ ${\href{/padicField/53.6.0.1}{6} }^{2}{,}\,{\href{/padicField/53.2.0.1}{2} }^{3}$ ${\href{/padicField/59.3.0.1}{3} }^{4}{,}\,{\href{/padicField/59.1.0.1}{1} }^{6}$

In the table, R denotes a ramified prime. Cycle lengths which are repeated in a cycle type are indicated by exponents.

# to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$ for $p=7$ in Sage:
 
p = 7; [(e, pr.norm().valuation(p)) for pr,e in K.factor(p)]
 
\\ to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$ for $p=7$ in Pari:
 
p = 7; pfac = idealprimedec(K, p); vector(length(pfac), j, [pfac[j][3], pfac[j][4]])
 
// to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$ for $p=7 in Magma:
 
p := 7; [<pr[2], Valuation(Norm(pr[1]), p)> : pr in Factorization(p*Integers(K))];
 
# to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$ for $p=7$ in Oscar:
 
p = 7; pfac = factor(ideal(ring_of_integers(K), p)); [(e, valuation(norm(pr),p)) for (pr,e) in pfac]
 

Local algebras for ramified primes

$p$LabelPolynomial $e$ $f$ $c$ Galois group Slope content
\(7\) Copy content Toggle raw display 7.2.0.1$x^{2} + 6 x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
7.2.0.1$x^{2} + 6 x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
7.2.0.1$x^{2} + 6 x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
7.6.4.3$x^{6} + 18 x^{5} + 117 x^{4} + 338 x^{3} + 477 x^{2} + 792 x + 1210$$3$$2$$4$$C_6$$[\ ]_{3}^{2}$
7.6.4.3$x^{6} + 18 x^{5} + 117 x^{4} + 338 x^{3} + 477 x^{2} + 792 x + 1210$$3$$2$$4$$C_6$$[\ ]_{3}^{2}$
\(23\) Copy content Toggle raw display 23.2.1.2$x^{2} + 23$$2$$1$$1$$C_2$$[\ ]_{2}$
23.2.1.2$x^{2} + 23$$2$$1$$1$$C_2$$[\ ]_{2}$
23.2.1.2$x^{2} + 23$$2$$1$$1$$C_2$$[\ ]_{2}$
23.6.3.2$x^{6} + 73 x^{4} + 36 x^{3} + 1591 x^{2} - 2412 x + 10467$$2$$3$$3$$C_6$$[\ ]_{2}^{3}$
23.6.3.2$x^{6} + 73 x^{4} + 36 x^{3} + 1591 x^{2} - 2412 x + 10467$$2$$3$$3$$C_6$$[\ ]_{2}^{3}$