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Properties

Label 16.0.922...000.1
Degree $16$
Signature $[0, 8]$
Discriminant $9.224\times 10^{19}$
Root discriminant \(17.69\)
Ramified primes $2,5,7$
Class number $1$
Class group trivial
Galois group $C_4\times C_2^2$ (as 16T2)

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Normalized defining polynomial

Copy content comment:Define the number field
 
Copy content sage:x = polygen(QQ); K.<a> = NumberField(x^16 + 3*x^14 + 5*x^12 + 3*x^10 - 11*x^8 + 12*x^6 + 80*x^4 + 192*x^2 + 256)
 
Copy content gp:K = bnfinit(y^16 + 3*y^14 + 5*y^12 + 3*y^10 - 11*y^8 + 12*y^6 + 80*y^4 + 192*y^2 + 256, 1)
 
Copy content magma:R<x> := PolynomialRing(Rationals()); K<a> := NumberField(x^16 + 3*x^14 + 5*x^12 + 3*x^10 - 11*x^8 + 12*x^6 + 80*x^4 + 192*x^2 + 256);
 
Copy content oscar:Qx, x = polynomial_ring(QQ); K, a = number_field(x^16 + 3*x^14 + 5*x^12 + 3*x^10 - 11*x^8 + 12*x^6 + 80*x^4 + 192*x^2 + 256)
 

\( x^{16} + 3x^{14} + 5x^{12} + 3x^{10} - 11x^{8} + 12x^{6} + 80x^{4} + 192x^{2} + 256 \) 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:  $16$
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:  $[0, 8]$
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:   \(92236816000000000000\) \(\medspace = 2^{16}\cdot 5^{12}\cdot 7^{8}\) 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:  \(17.69\)
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:  $2\cdot 5^{3/4}7^{1/2}\approx 17.693205386531027$
Ramified primes:   \(2\), \(5\), \(7\) 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:  \(\Q\)
$\Aut(K/\Q)$ $=$ $\Gal(K/\Q)$:   $C_2^2\times C_4$
Copy content comment:Autmorphisms
 
Copy content sage:K.automorphisms()
 
Copy content magma:Automorphisms(K);
 
Copy content oscar:automorphisms(K)
 
This field is Galois and abelian over $\Q$.
Conductor:  \(140=2^{2}\cdot 5\cdot 7\)
Dirichlet character group:    $\lbrace$$\chi_{140}(1,·)$, $\chi_{140}(69,·)$, $\chi_{140}(71,·)$, $\chi_{140}(139,·)$, $\chi_{140}(13,·)$, $\chi_{140}(83,·)$, $\chi_{140}(27,·)$, $\chi_{140}(29,·)$, $\chi_{140}(97,·)$, $\chi_{140}(99,·)$, $\chi_{140}(41,·)$, $\chi_{140}(43,·)$, $\chi_{140}(111,·)$, $\chi_{140}(113,·)$, $\chi_{140}(57,·)$, $\chi_{140}(127,·)$$\rbrace$
This is a CM field.
Reflex fields:  unavailable$^{128}$

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $\frac{1}{2}a^{9}-\frac{1}{2}a^{7}-\frac{1}{2}a^{5}-\frac{1}{2}a^{3}-\frac{1}{2}a$, $\frac{1}{44}a^{10}+\frac{1}{4}a^{8}-\frac{1}{4}a^{6}+\frac{1}{4}a^{4}-\frac{1}{4}a^{2}+\frac{3}{11}$, $\frac{1}{88}a^{11}+\frac{1}{8}a^{9}-\frac{1}{8}a^{7}+\frac{1}{8}a^{5}-\frac{1}{8}a^{3}+\frac{3}{22}a$, $\frac{1}{176}a^{12}-\frac{1}{176}a^{10}-\frac{5}{16}a^{8}-\frac{3}{16}a^{6}-\frac{5}{16}a^{4}+\frac{7}{22}a^{2}+\frac{2}{11}$, $\frac{1}{352}a^{13}-\frac{1}{352}a^{11}-\frac{5}{32}a^{9}-\frac{3}{32}a^{7}+\frac{11}{32}a^{5}-\frac{15}{44}a^{3}-\frac{9}{22}a$, $\frac{1}{704}a^{14}-\frac{1}{704}a^{12}-\frac{7}{704}a^{10}-\frac{19}{64}a^{8}+\frac{27}{64}a^{6}+\frac{7}{88}a^{4}+\frac{1}{22}a^{2}-\frac{2}{11}$, $\frac{1}{1408}a^{15}-\frac{1}{1408}a^{13}-\frac{7}{1408}a^{11}-\frac{19}{128}a^{9}+\frac{27}{128}a^{7}-\frac{81}{176}a^{5}-\frac{21}{44}a^{3}+\frac{9}{22}a$ 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:  Trivial group, which has order $1$
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:  Trivial group, which has order $1$
Copy content comment:Narrow class group
 
Copy content sage:K.narrow_class_group().invariants()
 
Copy content gp:bnfnarrow(K)
 
Copy content magma:NarrowClassGroup(K);
 
Relative class number:   $1$

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:  $7$
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:   \( -\frac{1}{88} a^{13} - \frac{1}{88} a^{3} \)  (order $20$) 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:   $\frac{1}{44}a^{12}+\frac{45}{44}a^{2}+1$, $\frac{17}{1408}a^{15}+\frac{3}{704}a^{14}+\frac{51}{1408}a^{13}+\frac{9}{704}a^{12}+\frac{85}{1408}a^{11}+\frac{15}{704}a^{10}-\frac{7}{128}a^{9}-\frac{5}{64}a^{8}-\frac{17}{128}a^{7}-\frac{3}{64}a^{6}+\frac{51}{352}a^{5}+\frac{9}{176}a^{4}+\frac{85}{88}a^{3}+\frac{15}{44}a^{2}+\frac{51}{22}a+\frac{9}{11}$, $\frac{1}{352}a^{15}-\frac{1}{88}a^{13}+\frac{1}{44}a^{12}+\frac{89}{352}a^{5}-\frac{1}{88}a^{3}+\frac{45}{44}a^{2}+1$, $\frac{13}{1408}a^{15}+\frac{19}{1408}a^{13}+\frac{21}{1408}a^{11}-\frac{7}{128}a^{9}-\frac{17}{128}a^{7}-\frac{19}{176}a^{5}-\frac{5}{88}a^{3}+\frac{3}{11}a$, $\frac{5}{1408}a^{15}-\frac{1}{1408}a^{13}+\frac{9}{1408}a^{11}-\frac{3}{128}a^{9}+\frac{11}{128}a^{7}-\frac{29}{352}a^{5}+\frac{35}{88}a^{3}-\frac{5}{11}a$, $\frac{9}{1408}a^{15}-\frac{3}{704}a^{14}-\frac{17}{1408}a^{13}-\frac{25}{704}a^{12}+\frac{9}{1408}a^{11}-\frac{15}{704}a^{10}-\frac{3}{128}a^{9}+\frac{5}{64}a^{8}+\frac{11}{128}a^{7}+\frac{3}{64}a^{6}+\frac{15}{88}a^{5}-\frac{9}{176}a^{4}-\frac{27}{44}a^{3}-\frac{15}{11}a^{2}+\frac{6}{11}a-\frac{9}{11}$, $\frac{3}{176}a^{15}-\frac{21}{704}a^{14}-\frac{35}{704}a^{12}+\frac{1}{22}a^{11}-\frac{21}{704}a^{10}+\frac{7}{64}a^{8}+\frac{17}{64}a^{6}+\frac{91}{176}a^{5}-\frac{35}{44}a^{4}-\frac{21}{11}a^{2}+\frac{23}{22}a-\frac{39}{11}$ 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:  \( 11381.1188025 \)
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

\[ \begin{aligned}\lim_{s\to 1} (s-1)\zeta_K(s) =\mathstrut & \frac{2^{r_1}\cdot (2\pi)^{r_2}\cdot R\cdot h}{w\cdot\sqrt{|D|}}\cr \approx\mathstrut &\frac{2^{0}\cdot(2\pi)^{8}\cdot 11381.1188025 \cdot 1}{20\cdot\sqrt{92236816000000000000}}\cr\approx \mathstrut & 0.143926828828 \end{aligned}\]

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^16 + 3*x^14 + 5*x^12 + 3*x^10 - 11*x^8 + 12*x^6 + 80*x^4 + 192*x^2 + 256) 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^16 + 3*x^14 + 5*x^12 + 3*x^10 - 11*x^8 + 12*x^6 + 80*x^4 + 192*x^2 + 256, 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^16 + 3*x^14 + 5*x^12 + 3*x^10 - 11*x^8 + 12*x^6 + 80*x^4 + 192*x^2 + 256); 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^16 + 3*x^14 + 5*x^12 + 3*x^10 - 11*x^8 + 12*x^6 + 80*x^4 + 192*x^2 + 256); 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

$C_2^2\times C_4$ (as 16T2):

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)
 
An abelian group of order 16
The 16 conjugacy class representatives for $C_4\times C_2^2$
Character table for $C_4\times C_2^2$

Intermediate fields

\(\Q(\sqrt{-1}) \), \(\Q(\sqrt{-35}) \), \(\Q(\sqrt{35}) \), \(\Q(\sqrt{5}) \), \(\Q(\sqrt{-5}) \), \(\Q(\sqrt{-7}) \), \(\Q(\sqrt{7}) \), \(\Q(i, \sqrt{35})\), \(\Q(i, \sqrt{5})\), \(\Q(i, \sqrt{7})\), \(\Q(\sqrt{5}, \sqrt{-7})\), \(\Q(\sqrt{-5}, \sqrt{7})\), \(\Q(\sqrt{5}, \sqrt{7})\), \(\Q(\sqrt{-5}, \sqrt{-7})\), \(\Q(\zeta_{5})\), \(\Q(\zeta_{20})^+\), 4.4.6125.1, 4.0.98000.1, 8.0.384160000.1, \(\Q(\zeta_{20})\), 8.0.9604000000.1, 8.0.37515625.1, 8.0.9604000000.2, 8.0.9604000000.3, 8.8.9604000000.1

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]
 

Frobenius cycle types

$p$ $2$ $3$ $5$ $7$ $11$ $13$ $17$ $19$ $23$ $29$ $31$ $37$ $41$ $43$ $47$ $53$ $59$
Cycle type R ${\href{/padicField/3.4.0.1}{4} }^{4}$ R R ${\href{/padicField/11.2.0.1}{2} }^{8}$ ${\href{/padicField/13.4.0.1}{4} }^{4}$ ${\href{/padicField/17.4.0.1}{4} }^{4}$ ${\href{/padicField/19.2.0.1}{2} }^{8}$ ${\href{/padicField/23.4.0.1}{4} }^{4}$ ${\href{/padicField/29.2.0.1}{2} }^{8}$ ${\href{/padicField/31.2.0.1}{2} }^{8}$ ${\href{/padicField/37.4.0.1}{4} }^{4}$ ${\href{/padicField/41.2.0.1}{2} }^{8}$ ${\href{/padicField/43.4.0.1}{4} }^{4}$ ${\href{/padicField/47.4.0.1}{4} }^{4}$ ${\href{/padicField/53.4.0.1}{4} }^{4}$ ${\href{/padicField/59.2.0.1}{2} }^{8}$

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 2.4.2.8a1.1$x^{8} + 2 x^{5} + 4 x^{4} + x^{2} + 4 x + 5$$2$$4$$8$$C_4\times C_2$$$[2]^{4}$$
2.4.2.8a1.1$x^{8} + 2 x^{5} + 4 x^{4} + x^{2} + 4 x + 5$$2$$4$$8$$C_4\times C_2$$$[2]^{4}$$
\(5\) Copy content Toggle raw display 5.2.4.6a1.2$x^{8} + 16 x^{7} + 104 x^{6} + 352 x^{5} + 664 x^{4} + 704 x^{3} + 416 x^{2} + 128 x + 21$$4$$2$$6$$C_4\times C_2$$$[\ ]_{4}^{2}$$
5.2.4.6a1.2$x^{8} + 16 x^{7} + 104 x^{6} + 352 x^{5} + 664 x^{4} + 704 x^{3} + 416 x^{2} + 128 x + 21$$4$$2$$6$$C_4\times C_2$$$[\ ]_{4}^{2}$$
\(7\) Copy content Toggle raw display 7.4.2.4a1.2$x^{8} + 10 x^{6} + 8 x^{5} + 31 x^{4} + 40 x^{3} + 46 x^{2} + 24 x + 16$$2$$4$$4$$C_4\times C_2$$$[\ ]_{2}^{4}$$
7.4.2.4a1.2$x^{8} + 10 x^{6} + 8 x^{5} + 31 x^{4} + 40 x^{3} + 46 x^{2} + 24 x + 16$$2$$4$$4$$C_4\times C_2$$$[\ ]_{2}^{4}$$

Spectrum of ring of integers

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