Properties

Label 8.0.5489031744.1
Degree $8$
Signature $[0, 4]$
Discriminant $5489031744$
Root discriminant \(16.50\)
Ramified primes $2,3,7$
Class number $2$
Class group [2]
Galois group $Q_8:C_2$ (as 8T11)

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Normalized defining polynomial

Copy content comment:Define the number field
 
Copy content sage:x = polygen(QQ); K.<a> = NumberField(x^8 - x^7 - 16*x^6 + 26*x^5 + 73*x^4 - 176*x^3 + 38*x^2 + 55*x + 67)
 
Copy content gp:K = bnfinit(y^8 - y^7 - 16*y^6 + 26*y^5 + 73*y^4 - 176*y^3 + 38*y^2 + 55*y + 67, 1)
 
Copy content magma:R<x> := PolynomialRing(Rationals()); K<a> := NumberField(x^8 - x^7 - 16*x^6 + 26*x^5 + 73*x^4 - 176*x^3 + 38*x^2 + 55*x + 67);
 
Copy content oscar:Qx, x = polynomial_ring(QQ); K, a = number_field(x^8 - x^7 - 16*x^6 + 26*x^5 + 73*x^4 - 176*x^3 + 38*x^2 + 55*x + 67)
 

\( x^{8} - x^{7} - 16x^{6} + 26x^{5} + 73x^{4} - 176x^{3} + 38x^{2} + 55x + 67 \) Copy content Toggle raw display

Copy content comment:Defining polynomial
 
Copy content sage:K.defining_polynomial()
 
Copy content gp:K.pol
 
Copy content magma:DefiningPolynomial(K);
 
Copy content oscar:defining_polynomial(K)
 

Invariants

Degree:  $8$
Copy content comment:Degree over Q
 
Copy content sage:K.degree()
 
Copy content gp:poldegree(K.pol)
 
Copy content magma:Degree(K);
 
Copy content oscar:degree(K)
 
Signature:  $[0, 4]$
Copy content comment:Signature
 
Copy content sage:K.signature()
 
Copy content gp:K.sign
 
Copy content magma:Signature(K);
 
Copy content oscar:signature(K)
 
Discriminant:   \(5489031744\) \(\medspace = 2^{6}\cdot 3^{6}\cdot 7^{6}\) Copy content Toggle raw display
Copy content comment:Discriminant
 
Copy content sage:K.disc()
 
Copy content gp:K.disc
 
Copy content magma:OK := Integers(K); Discriminant(OK);
 
Copy content oscar:OK = ring_of_integers(K); discriminant(OK)
 
Root discriminant:  \(16.50\)
Copy content comment:Root discriminant
 
Copy content sage:(K.disc().abs())^(1./K.degree())
 
Copy content gp:abs(K.disc)^(1/poldegree(K.pol))
 
Copy content magma:Abs(Discriminant(OK))^(1/Degree(K));
 
Copy content oscar:OK = ring_of_integers(K); (1.0 * abs(discriminant(OK)))^(1/degree(K))
 
Galois root discriminant:  $2^{3/2}3^{3/4}7^{3/4}\approx 27.746580271315977$
Ramified primes:   \(2\), \(3\), \(7\) Copy content Toggle raw display
Copy content comment:Ramified primes
 
Copy content sage:K.disc().support()
 
Copy content gp:factor(abs(K.disc))[,1]~
 
Copy content magma:PrimeDivisors(Discriminant(OK));
 
Copy content oscar:prime_divisors(discriminant(OK))
 
Discriminant root field:  \(\Q\)
$\Aut(K/\Q)$:   $C_4$
Copy content comment:Autmorphisms
 
Copy content sage:K.automorphisms()
 
Copy content magma:Automorphisms(K);
 
Copy content oscar:automorphisms(K)
 
This field is not Galois over $\Q$.
This is not a CM field.
Maximal CM subfield:  \(\Q(\sqrt{-3}, \sqrt{-7})\)

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $\frac{1}{43}a^{6}-\frac{14}{43}a^{5}-\frac{16}{43}a^{4}-\frac{13}{43}a^{3}+\frac{15}{43}a^{2}+\frac{17}{43}a+\frac{11}{43}$, $\frac{1}{9245}a^{7}-\frac{29}{9245}a^{6}+\frac{796}{9245}a^{5}-\frac{3772}{9245}a^{4}+\frac{3994}{9245}a^{3}-\frac{1068}{9245}a^{2}+\frac{2207}{9245}a+\frac{2974}{9245}$ Copy content Toggle raw display

Copy content comment:Integral basis
 
Copy content sage:K.integral_basis()
 
Copy content gp:K.zk
 
Copy content magma:IntegralBasis(K);
 
Copy content oscar:basis(OK)
 

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

Class group and class number

Ideal class group:  $C_{2}$, which has order $2$
Copy content comment:Class group
 
Copy content sage:K.class_group().invariants()
 
Copy content gp:K.clgp
 
Copy content magma:ClassGroup(K);
 
Copy content oscar:class_group(K)
 
Narrow class group:  $C_{2}$, which has order $2$
Copy content comment:Narrow class group
 
Copy content sage:K.narrow_class_group().invariants()
 
Copy content gp:bnfnarrow(K)
 
Copy content magma:NarrowClassGroup(K);
 

Unit group

Copy content comment:Unit group
 
Copy content sage:UK = K.unit_group()
 
Copy content magma:UK, fUK := UnitGroup(K);
 
Copy content oscar:UK, fUK = unit_group(OK)
 
Rank:  $3$
Copy content comment:Unit rank
 
Copy content sage:UK.rank()
 
Copy content gp:K.fu
 
Copy content magma:UnitRank(K);
 
Copy content oscar:rank(UK)
 
Torsion generator:   \( \frac{22}{9245} a^{7} + \frac{7}{9245} a^{6} - \frac{763}{9245} a^{5} - \frac{854}{9245} a^{4} + \frac{5523}{9245} a^{3} + \frac{4669}{9245} a^{2} - \frac{14441}{9245} a - \frac{1437}{9245} \)  (order $6$) Copy content Toggle raw display
Copy content comment:Generator for roots of unity
 
Copy content sage:UK.torsion_generator()
 
Copy content gp:K.tu[2]
 
Copy content magma:K!f(TU.1) where TU,f is TorsionUnitGroup(K);
 
Copy content oscar:torsion_units_generator(OK)
 
Fundamental units:   $\frac{102}{9245}a^{7}+\frac{267}{9245}a^{6}-\frac{938}{9245}a^{5}-\frac{1829}{9245}a^{4}+\frac{4908}{9245}a^{3}+\frac{4154}{9245}a^{2}-\frac{6656}{9245}a-\frac{3242}{9245}$, $\frac{481}{9245}a^{7}+\frac{671}{9245}a^{6}-\frac{6704}{9245}a^{5}-\frac{5107}{9245}a^{4}+\frac{29974}{9245}a^{3}+\frac{1432}{9245}a^{2}-\frac{2683}{9245}a-\frac{8071}{9245}$, $\frac{40}{1849}a^{7}+\frac{87}{1849}a^{6}-\frac{410}{1849}a^{5}-\frac{724}{1849}a^{4}+\frac{1176}{1849}a^{3}+\frac{1871}{1849}a^{2}+\frac{388}{1849}a-\frac{451}{1849}$ Copy content Toggle raw display
Copy content comment:Fundamental units
 
Copy content sage:UK.fundamental_units()
 
Copy content gp:K.fu
 
Copy content magma:[K|fUK(g): g in Generators(UK)];
 
Copy content oscar:[K(fUK(a)) for a in gens(UK)]
 
Regulator:  \( 66.8791967631 \)
Copy content comment:Regulator
 
Copy content sage:K.regulator()
 
Copy content gp:K.reg
 
Copy content magma:Regulator(K);
 
Copy content oscar:regulator(K)
 

Class number formula

\[ \begin{aligned}\lim_{s\to 1} (s-1)\zeta_K(s) =\mathstrut & \frac{2^{r_1}\cdot (2\pi)^{r_2}\cdot R\cdot h}{w\cdot\sqrt{|D|}}\cr \approx\mathstrut &\frac{2^{0}\cdot(2\pi)^{4}\cdot 66.8791967631 \cdot 2}{6\cdot\sqrt{5489031744}}\cr\approx \mathstrut & 0.468966041520 \end{aligned}\]

Copy content comment:Analytic class number formula
 
Copy content sage:# self-contained SageMath code snippet to compute the analytic class number formula x = polygen(QQ); K.<a> = NumberField(x^8 - x^7 - 16*x^6 + 26*x^5 + 73*x^4 - 176*x^3 + 38*x^2 + 55*x + 67) 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))))
 
Copy content gp:\\ self-contained Pari/GP code snippet to compute the analytic class number formula K = bnfinit(x^8 - x^7 - 16*x^6 + 26*x^5 + 73*x^4 - 176*x^3 + 38*x^2 + 55*x + 67, 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)))]
 
Copy content magma:/* self-contained Magma code snippet to compute the analytic class number formula */ Qx<x> := PolynomialRing(Rationals()); K<a> := NumberField(x^8 - x^7 - 16*x^6 + 26*x^5 + 73*x^4 - 176*x^3 + 38*x^2 + 55*x + 67); 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)));
 
Copy content oscar:# self-contained Oscar code snippet to compute the analytic class number formula Qx, x = polynomial_ring(QQ); K, a = number_field(x^8 - x^7 - 16*x^6 + 26*x^5 + 73*x^4 - 176*x^3 + 38*x^2 + 55*x + 67); 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

$D_4:C_2$ (as 8T11):

Copy content comment:Galois group
 
Copy content sage:K.galois_group(type='pari')
 
Copy content gp:polgalois(K.pol)
 
Copy content magma:G = GaloisGroup(K);
 
Copy content oscar:G, Gtx = galois_group(K); degree(K) > 1 ? (G, transitive_group_identification(G)) : (G, nothing)
 
A solvable group of order 16
The 10 conjugacy class representatives for $Q_8:C_2$
Character table for $Q_8:C_2$

Intermediate fields

\(\Q(\sqrt{-3}) \), \(\Q(\sqrt{-7}) \), \(\Q(\sqrt{21}) \), \(\Q(\sqrt{-3}, \sqrt{-7})\)

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

Copy content comment:Intermediate fields
 
Copy content sage:K.subfields()[1:-1]
 
Copy content gp:L = nfsubfields(K); L[2..length(L)]
 
Copy content magma:L := Subfields(K); L[2..#L];
 
Copy content oscar:subfields(K)[2:end-1]
 

Sibling fields

Galois closure: deg 16
Degree 8 siblings: 8.0.351298031616.5, 8.4.351298031616.1
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 R R ${\href{/padicField/5.2.0.1}{2} }^{4}$ R ${\href{/padicField/11.4.0.1}{4} }^{2}$ ${\href{/padicField/13.2.0.1}{2} }^{4}$ ${\href{/padicField/17.4.0.1}{4} }^{2}$ ${\href{/padicField/19.4.0.1}{4} }^{2}$ ${\href{/padicField/23.4.0.1}{4} }^{2}$ ${\href{/padicField/29.4.0.1}{4} }^{2}$ ${\href{/padicField/31.2.0.1}{2} }^{4}$ ${\href{/padicField/37.2.0.1}{2} }^{2}{,}\,{\href{/padicField/37.1.0.1}{1} }^{4}$ ${\href{/padicField/41.4.0.1}{4} }^{2}$ ${\href{/padicField/43.1.0.1}{1} }^{8}$ ${\href{/padicField/47.2.0.1}{2} }^{4}$ ${\href{/padicField/53.4.0.1}{4} }^{2}$ ${\href{/padicField/59.4.0.1}{4} }^{2}$

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

Copy content comment:Frobenius cycle types
 
Copy content sage:# to obtain a list of [e_i,f_i] for the factorization of the ideal pO_K for p=7 in Sage: p = 7; [(e, pr.norm().valuation(p)) for pr,e in K.factor(p)]
 
Copy content gp:\\ to obtain a list of [e_i,f_i] for the factorization of the ideal pO_K for p=7 in Pari: p = 7; pfac = idealprimedec(K, p); vector(length(pfac), j, [pfac[j][3], pfac[j][4]])
 
Copy content magma:// to obtain a list of [e_i,f_i] for the factorization of the ideal pO_K for p=7 in Magma: p := 7; [<pr[2], Valuation(Norm(pr[1]), p)> : pr in Factorization(p*Integers(K))];
 
Copy content oscar:# to obtain a list of [e_i,f_i] for the factorization of the ideal pO_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
\(2\) Copy content Toggle raw display 2.2.2.6a1.2$x^{4} + 2 x^{3} + 3 x^{2} + 10 x + 3$$2$$2$$6$$C_4$$$[3]^{2}$$
2.4.1.0a1.1$x^{4} + x + 1$$1$$4$$0$$C_4$$$[\ ]^{4}$$
\(3\) Copy content Toggle raw display 3.2.4.6a1.3$x^{8} + 8 x^{7} + 32 x^{6} + 80 x^{5} + 136 x^{4} + 160 x^{3} + 128 x^{2} + 67 x + 19$$4$$2$$6$$Q_8$$$[\ ]_{4}^{2}$$
\(7\) Copy content Toggle raw display 7.1.4.3a1.1$x^{4} + 7$$4$$1$$3$$D_{4}$$$[\ ]_{4}^{2}$$
7.1.4.3a1.1$x^{4} + 7$$4$$1$$3$$D_{4}$$$[\ ]_{4}^{2}$$

Artin representations

Label Dimension Conductor Artin stem field $G$ Ind $\chi(c)$
*16 1.1.1t1.a.a$1$ $1$ \(\Q\) $C_1$ $1$ $1$
1.8.2t1.b.a$1$ $ 2^{3}$ \(\Q(\sqrt{-2}) \) $C_2$ (as 2T1) $1$ $-1$
1.168.2t1.b.a$1$ $ 2^{3} \cdot 3 \cdot 7 $ \(\Q(\sqrt{-42}) \) $C_2$ (as 2T1) $1$ $-1$
*16 1.21.2t1.a.a$1$ $ 3 \cdot 7 $ \(\Q(\sqrt{21}) \) $C_2$ (as 2T1) $1$ $1$
1.56.2t1.a.a$1$ $ 2^{3} \cdot 7 $ \(\Q(\sqrt{14}) \) $C_2$ (as 2T1) $1$ $1$
*16 1.7.2t1.a.a$1$ $ 7 $ \(\Q(\sqrt{-7}) \) $C_2$ (as 2T1) $1$ $-1$
*16 1.3.2t1.a.a$1$ $ 3 $ \(\Q(\sqrt{-3}) \) $C_2$ (as 2T1) $1$ $-1$
1.24.2t1.a.a$1$ $ 2^{3} \cdot 3 $ \(\Q(\sqrt{6}) \) $C_2$ (as 2T1) $1$ $1$
*16 2.3528.8t11.a.a$2$ $ 2^{3} \cdot 3^{2} \cdot 7^{2}$ 8.0.5489031744.1 $Q_8:C_2$ (as 8T11) $0$ $0$
*16 2.3528.8t11.a.b$2$ $ 2^{3} \cdot 3^{2} \cdot 7^{2}$ 8.0.5489031744.1 $Q_8:C_2$ (as 8T11) $0$ $0$

Data is given for all irreducible representations of the Galois group for the Galois closure of this field. Those marked with * are summands in the permutation representation coming from this field. Representations which appear with multiplicity greater than one are indicated by exponents on the *.

Spectrum of ring of integers

(0)(0)(2)(3)(5)(7)(11)(13)(17)(19)(23)(29)(31)(37)(41)(43)(47)(53)(59)