Properties

Label 8.2.139968000000.3
Degree $8$
Signature $[2, 3]$
Discriminant $-139968000000$
Root discriminant \(24.73\)
Ramified primes $2,3,5$
Class number $2$
Class group [2]
Galois group $\textrm{GL(2,3)}$ (as 8T23)

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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 - 4*x^7 + 4*x^6 - 10*x^5 + 40*x^4 - 40*x^3 + 10*x^2 - 10*x - 5)
 
Copy content gp:K = bnfinit(y^8 - 4*y^7 + 4*y^6 - 10*y^5 + 40*y^4 - 40*y^3 + 10*y^2 - 10*y - 5, 1)
 
Copy content magma:R<x> := PolynomialRing(Rationals()); K<a> := NumberField(x^8 - 4*x^7 + 4*x^6 - 10*x^5 + 40*x^4 - 40*x^3 + 10*x^2 - 10*x - 5);
 
Copy content oscar:Qx, x = polynomial_ring(QQ); K, a = number_field(x^8 - 4*x^7 + 4*x^6 - 10*x^5 + 40*x^4 - 40*x^3 + 10*x^2 - 10*x - 5)
 

\( x^{8} - 4x^{7} + 4x^{6} - 10x^{5} + 40x^{4} - 40x^{3} + 10x^{2} - 10x - 5 \) 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:  $[2, 3]$
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:   \(-139968000000\) \(\medspace = -\,2^{12}\cdot 3^{7}\cdot 5^{6}\) 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:  \(24.73\)
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:(1.0 * dK)^(1/degree(K))
 
Galois root discriminant:  $2^{19/12}3^{7/8}5^{5/6}\approx 29.963112711597162$
Ramified primes:   \(2\), \(3\), \(5\) 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:  \(\Q(\sqrt{-3}) \)
$\Aut(K/\Q)$:   $C_2$
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.
This field has no CM subfields.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $\frac{1}{1049}a^{7}+\frac{326}{1049}a^{6}-\frac{463}{1049}a^{5}+\frac{354}{1049}a^{4}+\frac{421}{1049}a^{3}+\frac{422}{1049}a^{2}-\frac{247}{1049}a+\frac{302}{1049}$ 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:  $C_{2}\times C_{2}$, which has order $4$
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:  $4$
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:   \( -1 \)  (order $2$) 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:   $\frac{4}{1049}a^{7}+\frac{255}{1049}a^{6}-\frac{803}{1049}a^{5}+\frac{367}{1049}a^{4}-\frac{2512}{1049}a^{3}+\frac{7982}{1049}a^{2}-\frac{4135}{1049}a+\frac{2257}{1049}$, $\frac{375}{1049}a^{7}-\frac{1532}{1049}a^{6}+\frac{1558}{1049}a^{5}-\frac{3620}{1049}a^{4}+\frac{15211}{1049}a^{3}-\frac{15884}{1049}a^{2}+\frac{2834}{1049}a-\frac{3189}{1049}$, $\frac{793}{1049}a^{7}-\frac{3732}{1049}a^{6}+\frac{5236}{1049}a^{5}-\frac{8802}{1049}a^{4}+\frac{34888}{1049}a^{3}-\frac{52435}{1049}a^{2}+\frac{18125}{1049}a+\frac{10804}{1049}$, $\frac{502}{1049}a^{7}-\frac{2090}{1049}a^{6}+\frac{1501}{1049}a^{5}-\frac{3769}{1049}a^{4}+\frac{20424}{1049}a^{3}-\frac{15789}{1049}a^{2}-\frac{7555}{1049}a-\frac{501}{1049}$ 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:  \( 486.909901635 \)
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

\[ \begin{aligned}\lim_{s\to 1} (s-1)\zeta_K(s) =\mathstrut & \frac{2^{r_1}\cdot (2\pi)^{r_2}\cdot R\cdot h}{w\cdot\sqrt{|D|}}\cr \approx\mathstrut &\frac{2^{2}\cdot(2\pi)^{3}\cdot 486.909901635 \cdot 2}{2\cdot\sqrt{139968000000}}\cr\approx \mathstrut & 1.29131984167 \end{aligned}\]

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 - 4*x^7 + 4*x^6 - 10*x^5 + 40*x^4 - 40*x^3 + 10*x^2 - 10*x - 5) 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 - 4*x^7 + 4*x^6 - 10*x^5 + 40*x^4 - 40*x^3 + 10*x^2 - 10*x - 5, 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 - 4*x^7 + 4*x^6 - 10*x^5 + 40*x^4 - 40*x^3 + 10*x^2 - 10*x - 5); 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 = PolynomialRing(QQ); K, a = NumberField(x^8 - 4*x^7 + 4*x^6 - 10*x^5 + 40*x^4 - 40*x^3 + 10*x^2 - 10*x - 5); 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

$\GL(2,3)$ (as 8T23):

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); G, transitive_group_identification(G)
 
A solvable group of order 48
The 8 conjugacy class representatives for $\textrm{GL(2,3)}$
Character table for $\textrm{GL(2,3)}$

Intermediate fields

4.2.10800.2

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(b)]
 
Copy content magma:L := Subfields(K); L[2..#L];
 
Copy content oscar:subfields(K)[2:end-1]
 

Sibling fields

Degree 16 sibling: deg 16
Degree 24 sibling: deg 24
Arithmetically equivalent sibling: 8.2.139968000000.2
Minimal sibling: 8.2.139968000000.2

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 R ${\href{/padicField/7.3.0.1}{3} }^{2}{,}\,{\href{/padicField/7.1.0.1}{1} }^{2}$ ${\href{/padicField/11.8.0.1}{8} }$ ${\href{/padicField/13.3.0.1}{3} }^{2}{,}\,{\href{/padicField/13.1.0.1}{1} }^{2}$ ${\href{/padicField/17.8.0.1}{8} }$ ${\href{/padicField/19.3.0.1}{3} }^{2}{,}\,{\href{/padicField/19.1.0.1}{1} }^{2}$ ${\href{/padicField/23.8.0.1}{8} }$ ${\href{/padicField/29.8.0.1}{8} }$ ${\href{/padicField/31.3.0.1}{3} }^{2}{,}\,{\href{/padicField/31.1.0.1}{1} }^{2}$ ${\href{/padicField/37.4.0.1}{4} }^{2}$ ${\href{/padicField/41.2.0.1}{2} }^{3}{,}\,{\href{/padicField/41.1.0.1}{1} }^{2}$ ${\href{/padicField/43.6.0.1}{6} }{,}\,{\href{/padicField/43.2.0.1}{2} }$ ${\href{/padicField/47.8.0.1}{8} }$ ${\href{/padicField/53.2.0.1}{2} }^{3}{,}\,{\href{/padicField/53.1.0.1}{1} }^{2}$ ${\href{/padicField/59.8.0.1}{8} }$

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 2.1.8.12b1.1$x^{8} + 2 x^{5} + 2 x^{2} + 2$$8$$1$$12$$\textrm{GL(2,3)}$$$[\frac{4}{3}, \frac{4}{3}, 2]_{3}^{2}$$
\(3\) Copy content Toggle raw display 3.1.8.7a1.2$x^{8} + 6$$8$$1$$7$$QD_{16}$$$[\ ]_{8}^{2}$$
\(5\) Copy content Toggle raw display 5.1.2.1a1.2$x^{2} + 10$$2$$1$$1$$C_2$$$[\ ]_{2}$$
5.1.6.5a1.1$x^{6} + 5$$6$$1$$5$$D_{6}$$$[\ ]_{6}^{2}$$

Artin representations

Label Dimension Conductor Artin stem field $G$ Ind $\chi(c)$
* 1.1.1t1.a.a$1$ $1$ \(\Q\) $C_1$ $1$ $1$
1.3.2t1.a.a$1$ $ 3 $ \(\Q(\sqrt{-3}) \) $C_2$ (as 2T1) $1$ $-1$
2.300.3t2.a.a$2$ $ 2^{2} \cdot 3 \cdot 5^{2}$ 3.1.300.1 $S_3$ (as 3T2) $1$ $0$
2.3600.24t22.d.a$2$ $ 2^{4} \cdot 3^{2} \cdot 5^{2}$ 8.2.139968000000.3 $\textrm{GL(2,3)}$ (as 8T23) $0$ $0$
2.3600.24t22.d.b$2$ $ 2^{4} \cdot 3^{2} \cdot 5^{2}$ 8.2.139968000000.3 $\textrm{GL(2,3)}$ (as 8T23) $0$ $0$
3.3600.6t8.b.a$3$ $ 2^{4} \cdot 3^{2} \cdot 5^{2}$ 4.2.10800.2 $S_4$ (as 4T5) $1$ $-1$
* 3.10800.4t5.d.a$3$ $ 2^{4} \cdot 3^{3} \cdot 5^{2}$ 4.2.10800.2 $S_4$ (as 4T5) $1$ $1$
* 4.12960000.8t23.c.a$4$ $ 2^{8} \cdot 3^{4} \cdot 5^{4}$ 8.2.139968000000.3 $\textrm{GL(2,3)}$ (as 8T23) $1$ $0$

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)