Properties

Label 16.2.638966001996484375.1
Degree $16$
Signature $[2, 7]$
Discriminant $-6.390\times 10^{17}$
Root discriminant \(12.97\)
Ramified primes $5,29,31,89$
Class number $1$
Class group trivial
Galois group $C_4^4.C_2\wr D_4$ (as 16T1823)

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Show commands: Magma / Oscar / PariGP / SageMath

Normalized defining polynomial

sage: x = polygen(QQ); K.<a> = NumberField(x^16 - x^13 + 2*x^12 - 6*x^11 + 4*x^10 - x^9 + x^8 - x^7 + 4*x^6 - 6*x^5 + 2*x^4 - x^3 + 1)
 
gp: K = bnfinit(y^16 - y^13 + 2*y^12 - 6*y^11 + 4*y^10 - y^9 + y^8 - y^7 + 4*y^6 - 6*y^5 + 2*y^4 - y^3 + 1, 1)
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(x^16 - x^13 + 2*x^12 - 6*x^11 + 4*x^10 - x^9 + x^8 - x^7 + 4*x^6 - 6*x^5 + 2*x^4 - x^3 + 1);
 
oscar: Qx, x = polynomial_ring(QQ); K, a = number_field(x^16 - x^13 + 2*x^12 - 6*x^11 + 4*x^10 - x^9 + x^8 - x^7 + 4*x^6 - 6*x^5 + 2*x^4 - x^3 + 1)
 

\( x^{16} - x^{13} + 2x^{12} - 6x^{11} + 4x^{10} - x^{9} + x^{8} - x^{7} + 4x^{6} - 6x^{5} + 2x^{4} - x^{3} + 1 \) Copy content Toggle raw display

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

Invariants

Degree:  $16$
sage: K.degree()
 
gp: poldegree(K.pol)
 
magma: Degree(K);
 
oscar: degree(K)
 
Signature:  $[2, 7]$
sage: K.signature()
 
gp: K.sign
 
magma: Signature(K);
 
oscar: signature(K)
 
Discriminant:   \(-638966001996484375\) \(\medspace = -\,5^{8}\cdot 29^{2}\cdot 31\cdot 89^{4}\) 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:  \(12.97\)
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:  $5^{1/2}29^{1/2}31^{1/2}89^{1/2}\approx 632.4990118569357$
Ramified primes:   \(5\), \(29\), \(31\), \(89\) 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:  \(\Q(\sqrt{-31}) \)
$\card{ \Aut(K/\Q) }$:  $2$
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 \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $\frac{1}{68}a^{14}-\frac{5}{68}a^{13}+\frac{6}{17}a^{12}+\frac{5}{17}a^{11}+\frac{7}{34}a^{10}-\frac{7}{17}a^{9}-\frac{3}{34}a^{8}-\frac{11}{68}a^{7}-\frac{3}{34}a^{6}-\frac{7}{17}a^{5}+\frac{7}{34}a^{4}+\frac{5}{17}a^{3}+\frac{6}{17}a^{2}-\frac{5}{68}a+\frac{1}{68}$, $\frac{1}{68}a^{15}-\frac{1}{68}a^{13}+\frac{1}{17}a^{12}-\frac{11}{34}a^{11}-\frac{13}{34}a^{10}-\frac{5}{34}a^{9}+\frac{27}{68}a^{8}+\frac{7}{68}a^{7}+\frac{5}{34}a^{6}+\frac{5}{34}a^{5}+\frac{11}{34}a^{4}-\frac{3}{17}a^{3}-\frac{21}{68}a^{2}-\frac{6}{17}a+\frac{5}{68}$ Copy content Toggle raw display

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

Monogenic:  No
Index:  Not computed
Inessential primes:  $2$

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:   $a$, $\frac{14}{17}a^{15}+\frac{1}{17}a^{14}-\frac{2}{17}a^{13}-\frac{5}{17}a^{12}+\frac{35}{17}a^{11}-\frac{78}{17}a^{10}+\frac{36}{17}a^{9}+\frac{15}{17}a^{8}-\frac{32}{17}a^{7}-\frac{19}{17}a^{6}+\frac{61}{17}a^{5}-\frac{52}{17}a^{4}+\frac{5}{17}a^{3}+\frac{19}{17}a^{2}-\frac{18}{17}a-\frac{14}{17}$, $\frac{19}{68}a^{15}+\frac{47}{68}a^{14}+\frac{9}{34}a^{13}-\frac{5}{17}a^{12}-\frac{11}{34}a^{11}-\frac{10}{17}a^{10}-\frac{73}{34}a^{9}+\frac{95}{68}a^{8}+\frac{6}{17}a^{7}+\frac{11}{17}a^{6}+\frac{15}{34}a^{5}-\frac{3}{17}a^{4}-\frac{43}{17}a^{3}+\frac{49}{68}a^{2}-\frac{11}{68}a+\frac{3}{34}$, $\frac{3}{34}a^{15}-\frac{19}{68}a^{14}-\frac{47}{68}a^{13}-\frac{6}{17}a^{12}+\frac{8}{17}a^{11}-\frac{7}{34}a^{10}+\frac{16}{17}a^{9}+\frac{35}{17}a^{8}-\frac{89}{68}a^{7}-\frac{15}{34}a^{6}-\frac{5}{17}a^{5}-\frac{33}{34}a^{4}+\frac{6}{17}a^{3}+\frac{83}{34}a^{2}+\frac{19}{68}a+\frac{11}{68}$, $\frac{1}{68}a^{15}+\frac{3}{17}a^{14}+\frac{7}{68}a^{13}+\frac{5}{17}a^{12}+\frac{7}{34}a^{11}+\frac{3}{34}a^{10}-\frac{37}{34}a^{9}+\frac{23}{68}a^{8}-\frac{57}{68}a^{7}-\frac{31}{34}a^{6}+\frac{41}{34}a^{5}-\frac{7}{34}a^{4}-\frac{11}{17}a^{3}+\frac{63}{68}a^{2}-\frac{21}{17}a-\frac{3}{4}$, $\frac{11}{34}a^{15}-\frac{10}{17}a^{14}-\frac{13}{34}a^{13}-\frac{14}{17}a^{12}+\frac{19}{17}a^{11}-\frac{45}{17}a^{10}+\frac{72}{17}a^{9}-\frac{59}{34}a^{8}+\frac{59}{34}a^{7}-\frac{21}{17}a^{6}+\frac{12}{17}a^{5}-\frac{53}{17}a^{4}+\frac{57}{17}a^{3}-\frac{31}{34}a^{2}+\frac{20}{17}a+\frac{35}{34}$, $\frac{11}{34}a^{15}-\frac{10}{17}a^{14}-\frac{13}{34}a^{13}-\frac{14}{17}a^{12}+\frac{19}{17}a^{11}-\frac{45}{17}a^{10}+\frac{72}{17}a^{9}-\frac{59}{34}a^{8}+\frac{59}{34}a^{7}-\frac{21}{17}a^{6}+\frac{12}{17}a^{5}-\frac{53}{17}a^{4}+\frac{57}{17}a^{3}-\frac{31}{34}a^{2}+\frac{20}{17}a+\frac{1}{34}$, $\frac{27}{68}a^{15}-\frac{4}{17}a^{14}-\frac{15}{68}a^{13}-\frac{1}{17}a^{12}+\frac{53}{34}a^{11}-\frac{89}{34}a^{10}+\frac{55}{34}a^{9}+\frac{9}{68}a^{8}-\frac{43}{68}a^{7}-\frac{55}{34}a^{6}+\frac{53}{34}a^{5}-\frac{19}{34}a^{4}+\frac{9}{17}a^{3}-\frac{67}{68}a^{2}+\frac{11}{17}a-\frac{1}{4}$ 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:  \( 298.472419612 \)
sage: K.regulator()
 
gp: K.reg
 
magma: Regulator(K);
 
oscar: regulator(K)
 

Class number formula

\[ \begin{aligned}\lim_{s\to 1} (s-1)\zeta_K(s) =\mathstrut & \frac{2^{r_1}\cdot (2\pi)^{r_2}\cdot R\cdot h}{w\cdot\sqrt{|D|}}\cr \approx\mathstrut &\frac{2^{2}\cdot(2\pi)^{7}\cdot 298.472419612 \cdot 1}{2\cdot\sqrt{638966001996484375}}\cr\approx \mathstrut & 0.288705066228 \end{aligned}\]

# self-contained SageMath code snippet to compute the analytic class number formula
 
x = polygen(QQ); K.<a> = NumberField(x^16 - x^13 + 2*x^12 - 6*x^11 + 4*x^10 - x^9 + x^8 - x^7 + 4*x^6 - 6*x^5 + 2*x^4 - x^3 + 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^16 - x^13 + 2*x^12 - 6*x^11 + 4*x^10 - x^9 + x^8 - x^7 + 4*x^6 - 6*x^5 + 2*x^4 - x^3 + 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^16 - x^13 + 2*x^12 - 6*x^11 + 4*x^10 - x^9 + x^8 - x^7 + 4*x^6 - 6*x^5 + 2*x^4 - x^3 + 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^16 - x^13 + 2*x^12 - 6*x^11 + 4*x^10 - x^9 + x^8 - x^7 + 4*x^6 - 6*x^5 + 2*x^4 - x^3 + 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

$C_4^4.C_2\wr D_4$ (as 16T1823):

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 32768
The 230 conjugacy class representatives for $C_4^4.C_2\wr D_4$
Character table for $C_4^4.C_2\wr D_4$

Intermediate fields

\(\Q(\sqrt{5}) \), 4.4.2225.1, 8.4.143568125.1

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 16 siblings: data not computed
Degree 32 siblings: data not computed
Minimal sibling: This field is its own minimal sibling

Frobenius cycle types

$p$ $2$ $3$ $5$ $7$ $11$ $13$ $17$ $19$ $23$ $29$ $31$ $37$ $41$ $43$ $47$ $53$ $59$
Cycle type ${\href{/padicField/2.8.0.1}{8} }{,}\,{\href{/padicField/2.4.0.1}{4} }{,}\,{\href{/padicField/2.2.0.1}{2} }^{2}$ $16$ R ${\href{/padicField/7.8.0.1}{8} }^{2}$ ${\href{/padicField/11.8.0.1}{8} }{,}\,{\href{/padicField/11.2.0.1}{2} }^{4}$ ${\href{/padicField/13.8.0.1}{8} }{,}\,{\href{/padicField/13.4.0.1}{4} }^{2}$ ${\href{/padicField/17.4.0.1}{4} }^{3}{,}\,{\href{/padicField/17.2.0.1}{2} }^{2}$ ${\href{/padicField/19.8.0.1}{8} }{,}\,{\href{/padicField/19.4.0.1}{4} }{,}\,{\href{/padicField/19.2.0.1}{2} }^{2}$ ${\href{/padicField/23.8.0.1}{8} }{,}\,{\href{/padicField/23.4.0.1}{4} }^{2}$ R R $16$ ${\href{/padicField/41.4.0.1}{4} }^{3}{,}\,{\href{/padicField/41.2.0.1}{2} }{,}\,{\href{/padicField/41.1.0.1}{1} }^{2}$ $16$ ${\href{/padicField/47.8.0.1}{8} }{,}\,{\href{/padicField/47.4.0.1}{4} }{,}\,{\href{/padicField/47.2.0.1}{2} }^{2}$ ${\href{/padicField/53.8.0.1}{8} }{,}\,{\href{/padicField/53.4.0.1}{4} }^{2}$ ${\href{/padicField/59.4.0.1}{4} }^{3}{,}\,{\href{/padicField/59.2.0.1}{2} }{,}\,{\href{/padicField/59.1.0.1}{1} }^{2}$

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
\(5\) Copy content Toggle raw display 5.16.8.1$x^{16} + 160 x^{15} + 11240 x^{14} + 453600 x^{13} + 11536702 x^{12} + 190484240 x^{11} + 2020220586 x^{10} + 13041178608 x^{9} + 45239382035 x^{8} + 65384309200 x^{7} + 52374358166 x^{6} + 35488260768 x^{5} + 46408266743 x^{4} + 66345171264 x^{3} + 136057926318 x^{2} + 159173865296 x + 74196697609$$2$$8$$8$$C_8\times C_2$$[\ ]_{2}^{8}$
\(29\) Copy content Toggle raw display 29.2.1.1$x^{2} + 29$$2$$1$$1$$C_2$$[\ ]_{2}$
29.2.1.1$x^{2} + 29$$2$$1$$1$$C_2$$[\ ]_{2}$
29.4.0.1$x^{4} + 2 x^{2} + 15 x + 2$$1$$4$$0$$C_4$$[\ ]^{4}$
29.4.0.1$x^{4} + 2 x^{2} + 15 x + 2$$1$$4$$0$$C_4$$[\ ]^{4}$
29.4.0.1$x^{4} + 2 x^{2} + 15 x + 2$$1$$4$$0$$C_4$$[\ ]^{4}$
\(31\) Copy content Toggle raw display 31.2.1.1$x^{2} + 93$$2$$1$$1$$C_2$$[\ ]_{2}$
31.2.0.1$x^{2} + 29 x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
31.2.0.1$x^{2} + 29 x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
31.2.0.1$x^{2} + 29 x + 3$$1$$2$$0$$C_2$$[\ ]^{2}$
31.4.0.1$x^{4} + 3 x^{2} + 16 x + 3$$1$$4$$0$$C_4$$[\ ]^{4}$
31.4.0.1$x^{4} + 3 x^{2} + 16 x + 3$$1$$4$$0$$C_4$$[\ ]^{4}$
\(89\) Copy content Toggle raw display 89.2.1.2$x^{2} + 267$$2$$1$$1$$C_2$$[\ ]_{2}$
89.2.1.2$x^{2} + 267$$2$$1$$1$$C_2$$[\ ]_{2}$
89.4.2.1$x^{4} + 12268 x^{3} + 38122404 x^{2} + 3045212032 x + 156142232$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
89.8.0.1$x^{8} + 65 x^{3} + 40 x^{2} + 79 x + 3$$1$$8$$0$$C_8$$[\ ]^{8}$