Properties

Label 16.0.88138633985...0625.2
Degree $16$
Signature $[0, 8]$
Discriminant $5^{8}\cdot 41^{12}$
Root discriminant $36.23$
Ramified primes $5, 41$
Class number $9$ (GRH)
Class group $[3, 3]$ (GRH)
Galois group $C_2^2 : C_4$ (as 16T10)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![65536, 0, 16384, 0, -3072, 0, -29008, 0, 15464, 0, -1813, 0, -12, 0, 4, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^16 + 4*x^14 - 12*x^12 - 1813*x^10 + 15464*x^8 - 29008*x^6 - 3072*x^4 + 16384*x^2 + 65536)
 
gp: K = bnfinit(x^16 + 4*x^14 - 12*x^12 - 1813*x^10 + 15464*x^8 - 29008*x^6 - 3072*x^4 + 16384*x^2 + 65536, 1)
 

Normalized defining polynomial

\( x^{16} + 4 x^{14} - 12 x^{12} - 1813 x^{10} + 15464 x^{8} - 29008 x^{6} - 3072 x^{4} + 16384 x^{2} + 65536 \)

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

Invariants

Degree:  $16$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[0, 8]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(8813863398580541437890625=5^{8}\cdot 41^{12}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $36.23$
magma: Abs(Discriminant(Integers(K)))^(1/Degree(K));
 
sage: (K.disc().abs())^(1./K.degree())
 
gp: abs(K.disc)^(1/poldegree(K.pol))
 
Ramified primes:  $5, 41$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois over $\Q$.
This is a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $\frac{1}{2} a^{4} - \frac{1}{2} a$, $\frac{1}{2} a^{5} - \frac{1}{2} a^{2}$, $\frac{1}{2} a^{6} - \frac{1}{2} a^{3}$, $\frac{1}{2} a^{7} - \frac{1}{2} a$, $\frac{1}{24} a^{8} - \frac{1}{4} a^{7} - \frac{1}{6} a^{6} + \frac{1}{6} a^{4} + \frac{11}{24} a^{2} + \frac{1}{4} a - \frac{1}{3}$, $\frac{1}{48} a^{9} + \frac{1}{6} a^{7} + \frac{1}{12} a^{5} + \frac{11}{48} a^{3} + \frac{1}{12} a$, $\frac{1}{192} a^{10} - \frac{1}{4} a^{7} - \frac{1}{16} a^{6} + \frac{9}{64} a^{4} + \frac{5}{16} a^{2} + \frac{1}{4} a + \frac{1}{3}$, $\frac{1}{768} a^{11} - \frac{1}{96} a^{9} - \frac{43}{192} a^{7} - \frac{5}{768} a^{5} + \frac{41}{192} a^{3} - \frac{1}{3} a$, $\frac{1}{9200640} a^{12} - \frac{1}{1536} a^{11} - \frac{287}{383360} a^{10} + \frac{1}{192} a^{9} + \frac{6599}{766720} a^{8} - \frac{53}{384} a^{7} - \frac{300247}{3066880} a^{6} + \frac{5}{1536} a^{5} + \frac{180459}{766720} a^{4} - \frac{41}{384} a^{3} + \frac{1199}{71880} a^{2} - \frac{1}{12} a + \frac{1001}{5990}$, $\frac{1}{18401280} a^{13} + \frac{1273}{4600320} a^{11} - \frac{4163}{4600320} a^{9} - \frac{2961301}{18401280} a^{7} + \frac{263201}{2300160} a^{5} - \frac{51711}{383360} a^{3} - \frac{2987}{35940} a - \frac{1}{2}$, $\frac{1}{3165020160} a^{14} - \frac{1}{18401280} a^{12} - \frac{98797}{52750336} a^{10} - \frac{1}{96} a^{9} + \frac{14156587}{3165020160} a^{8} + \frac{1}{6} a^{7} - \frac{9307781}{395627520} a^{6} - \frac{1}{24} a^{5} - \frac{2681309}{39562752} a^{4} + \frac{37}{96} a^{3} + \frac{26299}{71880} a^{2} + \frac{5}{24} a + \frac{141128}{386355}$, $\frac{1}{12660080640} a^{15} - \frac{1}{73605120} a^{13} + \frac{115721}{633004032} a^{11} - \frac{1}{384} a^{10} + \frac{26698169}{4220026880} a^{9} - \frac{1}{48} a^{8} + \frac{47724553}{527503360} a^{7} + \frac{11}{96} a^{6} + \frac{3397343}{158251008} a^{5} - \frac{59}{384} a^{4} + \frac{216011}{1150080} a^{3} - \frac{37}{96} a^{2} - \frac{315791}{772710} a - \frac{1}{2}$

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

Class group and class number

$C_{3}\times C_{3}$, which has order $9$ (assuming GRH)

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

Unit group

magma: UK, f := UnitGroup(K);
 
sage: UK = K.unit_group()
 
Rank:  $7$
magma: UnitRank(K);
 
sage: UK.rank()
 
gp: K.fu
 
Torsion generator:  \( -1 \) (order $2$)
magma: K!f(TU.1) where TU,f is TorsionUnitGroup(K);
 
sage: UK.torsion_generator()
 
gp: K.tu[2]
 
Fundamental units:  Units are too long to display, but can be downloaded with other data for this field from 'Stored data to gp' link to the right (assuming GRH)
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 525465.124463 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_2^2:C_4$ (as 16T10):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 16
The 10 conjugacy class representatives for $C_2^2 : C_4$
Character table for $C_2^2 : C_4$

Intermediate fields

\(\Q(\sqrt{5}) \), \(\Q(\sqrt{205}) \), \(\Q(\sqrt{41}) \), \(\Q(\sqrt{5}, \sqrt{41})\), 4.0.1723025.1 x2, 4.0.344605.1 x2, 4.0.1025.1 x2, 4.0.8405.1 x2, 4.4.68921.1, 4.4.1723025.1, 8.0.2968815150625.2, 8.0.1766100625.1, 8.8.2968815150625.1, 8.0.118752606025.1 x2, 8.0.2968815150625.3 x2

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

Sibling fields

Degree 8 siblings: data not computed

Frobenius cycle types

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59
Cycle type ${\href{/LocalNumberField/2.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/3.4.0.1}{4} }^{4}$ R ${\href{/LocalNumberField/7.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/11.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/13.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/17.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/19.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/23.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/29.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/31.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/37.2.0.1}{2} }^{8}$ R ${\href{/LocalNumberField/43.2.0.1}{2} }^{8}$ ${\href{/LocalNumberField/47.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/53.4.0.1}{4} }^{4}$ ${\href{/LocalNumberField/59.1.0.1}{1} }^{16}$

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

magma: p := 7; // to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$:
 
magma: idealfactors := Factorization(p*Integers(K)); // get the data
 
magma: [<primefactor[2], Valuation(Norm(primefactor[1]), p)> : primefactor in idealfactors];
 
sage: p = 7; # to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$:
 
sage: [(e, pr.norm().valuation(p)) for pr,e in K.factor(p)]
 
gp: p = 7; \\ to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$:
 
gp: idealfactors = idealprimedec(K, p); \\ get the data
 
gp: vector(length(idealfactors), j, [idealfactors[j][3], idealfactors[j][4]])
 

Local algebras for ramified primes

$p$LabelPolynomial $e$ $f$ $c$ Galois group Slope content
$5$5.4.2.1$x^{4} + 15 x^{2} + 100$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
5.4.2.1$x^{4} + 15 x^{2} + 100$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
5.4.2.1$x^{4} + 15 x^{2} + 100$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
5.4.2.1$x^{4} + 15 x^{2} + 100$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
$41$41.8.6.1$x^{8} - 9881 x^{4} + 34857216$$4$$2$$6$$C_4\times C_2$$[\ ]_{4}^{2}$
41.8.6.1$x^{8} - 9881 x^{4} + 34857216$$4$$2$$6$$C_4\times C_2$$[\ ]_{4}^{2}$