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Properties

Label 8.0.12496630500612241.1
Degree $8$
Signature $[0, 4]$
Discriminant $1.250\times 10^{16}$
Root discriminant \(102.83\)
Ramified primes $97,109$
Class number $225$
Class group [15, 15]
Galois group $D_4$ (as 8T4)

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Show commands: Magma / Oscar / PariGP / SageMath

Normalized defining polynomial

sage: x = polygen(QQ); K.<a> = NumberField(x^8 - 2*x^7 + 67*x^6 - 344*x^5 + 2755*x^4 - 10562*x^3 + 54552*x^2 - 235224*x + 439344)
 
gp: K = bnfinit(y^8 - 2*y^7 + 67*y^6 - 344*y^5 + 2755*y^4 - 10562*y^3 + 54552*y^2 - 235224*y + 439344, 1)
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(x^8 - 2*x^7 + 67*x^6 - 344*x^5 + 2755*x^4 - 10562*x^3 + 54552*x^2 - 235224*x + 439344);
 
oscar: Qx, x = polynomial_ring(QQ); K, a = number_field(x^8 - 2*x^7 + 67*x^6 - 344*x^5 + 2755*x^4 - 10562*x^3 + 54552*x^2 - 235224*x + 439344)
 

\( x^{8} - 2x^{7} + 67x^{6} - 344x^{5} + 2755x^{4} - 10562x^{3} + 54552x^{2} - 235224x + 439344 \) Copy content Toggle raw display

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

Invariants

Degree:  $8$
sage: K.degree()
 
gp: poldegree(K.pol)
 
magma: Degree(K);
 
oscar: degree(K)
 
Signature:  $[0, 4]$
sage: K.signature()
 
gp: K.sign
 
magma: Signature(K);
 
oscar: signature(K)
 
Discriminant:   \(12496630500612241\) \(\medspace = 97^{4}\cdot 109^{4}\) 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:  \(102.83\)
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:  $97^{1/2}109^{1/2}\approx 102.82509421342633$
Ramified primes:   \(97\), \(109\) 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:  \(\Q\)
$\card{ \Gal(K/\Q) }$:  $8$
sage: K.automorphisms()
 
magma: Automorphisms(K);
 
oscar: automorphisms(K)
 
This field is Galois over $\Q$.
This is a CM field.
Reflex fields:  4.0.1025581.1$^{4}$, 4.0.1152457.1$^{4}$

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

$1$, $a$, $a^{2}$, $\frac{1}{6}a^{3}-\frac{1}{2}a^{2}-\frac{1}{6}a$, $\frac{1}{6}a^{4}+\frac{1}{3}a^{2}-\frac{1}{2}a$, $\frac{1}{6}a^{5}-\frac{1}{2}a^{2}+\frac{1}{3}a$, $\frac{1}{108}a^{6}+\frac{1}{18}a^{5}+\frac{7}{108}a^{4}+\frac{19}{108}a^{2}-\frac{1}{18}a$, $\frac{1}{39676229136}a^{7}-\frac{2653735}{1102117476}a^{6}+\frac{1860756019}{39676229136}a^{5}-\frac{286729849}{6612704856}a^{4}+\frac{2639431999}{39676229136}a^{3}-\frac{8383904}{17586981}a^{2}+\frac{107756467}{551058738}a-\frac{812339}{1625542}$ 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:  $2$, $3$

Class group and class number

$C_{15}\times C_{15}$, which has order $225$

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

Relative class number: $225$

Unit group

sage: UK = K.unit_group()
 
magma: UK, fUK := UnitGroup(K);
 
oscar: UK, fUK = unit_group(OK)
 
Rank:  $3$
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:   $\frac{170725}{351117072}a^{7}-\frac{8300}{2438313}a^{6}+\frac{11488375}{351117072}a^{5}-\frac{15935575}{58519512}a^{4}+\frac{692763475}{351117072}a^{3}-\frac{5492525}{622548}a^{2}+\frac{32755875}{1625542}a-\frac{28489219}{1625542}$, $\frac{35279485}{4959528642}a^{7}-\frac{401774035}{9919057284}a^{6}+\frac{1394857189}{4959528642}a^{5}-\frac{12550581895}{9919057284}a^{4}+\frac{39345272395}{4959528642}a^{3}-\frac{5694602405}{211043772}a^{2}+\frac{6553641326}{826588107}a+\frac{78274470}{812771}$, $\frac{62021}{1867644}a^{7}+\frac{47227}{311274}a^{6}+\frac{1683671}{1867644}a^{5}-\frac{314657}{155637}a^{4}-\frac{11009581}{1867644}a^{3}-\frac{2315261}{103758}a^{2}+\frac{2302743}{17293}a+\frac{2321119}{17293}$ 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:  \( 9483.49848207 \)
sage: K.regulator()
 
gp: K.reg
 
magma: Regulator(K);
 
oscar: regulator(K)
 

Class number formula

\[ \begin{aligned}\lim_{s\to 1} (s-1)\zeta_K(s) =\mathstrut & \frac{2^{r_1}\cdot (2\pi)^{r_2}\cdot R\cdot h}{w\cdot\sqrt{|D|}}\cr \approx\mathstrut &\frac{2^{0}\cdot(2\pi)^{4}\cdot 9483.49848207 \cdot 225}{2\cdot\sqrt{12496630500612241}}\cr\approx \mathstrut & 14.8745594053 \end{aligned}\]

# self-contained SageMath code snippet to compute the analytic class number formula
 
x = polygen(QQ); K.<a> = NumberField(x^8 - 2*x^7 + 67*x^6 - 344*x^5 + 2755*x^4 - 10562*x^3 + 54552*x^2 - 235224*x + 439344)
 
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^8 - 2*x^7 + 67*x^6 - 344*x^5 + 2755*x^4 - 10562*x^3 + 54552*x^2 - 235224*x + 439344, 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^8 - 2*x^7 + 67*x^6 - 344*x^5 + 2755*x^4 - 10562*x^3 + 54552*x^2 - 235224*x + 439344);
 
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^8 - 2*x^7 + 67*x^6 - 344*x^5 + 2755*x^4 - 10562*x^3 + 54552*x^2 - 235224*x + 439344);
 
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

$D_4$ (as 8T4):

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 8
The 5 conjugacy class representatives for $D_4$
Character table for $D_4$

Intermediate fields

\(\Q(\sqrt{10573}) \), \(\Q(\sqrt{97}) \), \(\Q(\sqrt{109}) \), \(\Q(\sqrt{97}, \sqrt{109})\), 4.0.1025581.1 x2, 4.0.1152457.1 x2

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 4 siblings: 4.0.1152457.1, 4.0.1025581.1
Minimal sibling: 4.0.1025581.1

Frobenius cycle types

$p$ $2$ $3$ $5$ $7$ $11$ $13$ $17$ $19$ $23$ $29$ $31$ $37$ $41$ $43$ $47$ $53$ $59$
Cycle type ${\href{/padicField/2.2.0.1}{2} }^{4}$ ${\href{/padicField/3.1.0.1}{1} }^{8}$ ${\href{/padicField/5.2.0.1}{2} }^{4}$ ${\href{/padicField/7.2.0.1}{2} }^{4}$ ${\href{/padicField/11.2.0.1}{2} }^{4}$ ${\href{/padicField/13.4.0.1}{4} }^{2}$ ${\href{/padicField/17.4.0.1}{4} }^{2}$ ${\href{/padicField/19.4.0.1}{4} }^{2}$ ${\href{/padicField/23.4.0.1}{4} }^{2}$ ${\href{/padicField/29.2.0.1}{2} }^{4}$ ${\href{/padicField/31.2.0.1}{2} }^{4}$ ${\href{/padicField/37.4.0.1}{4} }^{2}$ ${\href{/padicField/41.4.0.1}{4} }^{2}$ ${\href{/padicField/43.2.0.1}{2} }^{4}$ ${\href{/padicField/47.2.0.1}{2} }^{4}$ ${\href{/padicField/53.2.0.1}{2} }^{4}$ ${\href{/padicField/59.4.0.1}{4} }^{2}$

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
\(97\) Copy content Toggle raw display 97.4.2.1$x^{4} + 10474 x^{3} + 27919909 x^{2} + 2585716380 x + 183392493$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
97.4.2.1$x^{4} + 10474 x^{3} + 27919909 x^{2} + 2585716380 x + 183392493$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
\(109\) Copy content Toggle raw display 109.2.1.1$x^{2} + 109$$2$$1$$1$$C_2$$[\ ]_{2}$
109.2.1.1$x^{2} + 109$$2$$1$$1$$C_2$$[\ ]_{2}$
109.2.1.1$x^{2} + 109$$2$$1$$1$$C_2$$[\ ]_{2}$
109.2.1.1$x^{2} + 109$$2$$1$$1$$C_2$$[\ ]_{2}$

Artin representations

Label Dimension Conductor Artin stem field $G$ Ind $\chi(c)$
* 1.1.1t1.a.a$1$ $1$ \(\Q\) $C_1$ $1$ $1$
* 1.109.2t1.a.a$1$ $ 109 $ \(\Q(\sqrt{109}) \) $C_2$ (as 2T1) $1$ $1$
* 1.97.2t1.a.a$1$ $ 97 $ \(\Q(\sqrt{97}) \) $C_2$ (as 2T1) $1$ $1$
* 1.10573.2t1.a.a$1$ $ 97 \cdot 109 $ \(\Q(\sqrt{10573}) \) $C_2$ (as 2T1) $1$ $1$
*2 2.10573.4t3.b.a$2$ $ 97 \cdot 109 $ 8.0.12496630500612241.1 $D_4$ (as 8T4) $1$ $-2$

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 *.