Properties

Label 40.0.10240000000...0000.1
Degree $40$
Signature $[0, 20]$
Discriminant $2^{80}\cdot 5^{70}$
Root discriminant $66.87$
Ramified primes $2, 5$
Class number $542102$ (GRH)
Class group $[542102]$ (GRH)
Galois group $C_2\times C_{20}$ (as 40T2)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, 0, 300, 0, 12475, 0, 172920, 0, 1221495, 0, 5226012, 0, 14855725, 0, 29715200, 0, 43459480, 0, 47720380, 0, 40060019, 0, 26013000, 0, 13147875, 0, 5178240, 0, 1582240, 0, 371008, 0, 65450, 0, 8400, 0, 740, 0, 40, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^40 + 40*x^38 + 740*x^36 + 8400*x^34 + 65450*x^32 + 371008*x^30 + 1582240*x^28 + 5178240*x^26 + 13147875*x^24 + 26013000*x^22 + 40060019*x^20 + 47720380*x^18 + 43459480*x^16 + 29715200*x^14 + 14855725*x^12 + 5226012*x^10 + 1221495*x^8 + 172920*x^6 + 12475*x^4 + 300*x^2 + 1)
 
gp: K = bnfinit(x^40 + 40*x^38 + 740*x^36 + 8400*x^34 + 65450*x^32 + 371008*x^30 + 1582240*x^28 + 5178240*x^26 + 13147875*x^24 + 26013000*x^22 + 40060019*x^20 + 47720380*x^18 + 43459480*x^16 + 29715200*x^14 + 14855725*x^12 + 5226012*x^10 + 1221495*x^8 + 172920*x^6 + 12475*x^4 + 300*x^2 + 1, 1)
 

Normalized defining polynomial

\( x^{40} + 40 x^{38} + 740 x^{36} + 8400 x^{34} + 65450 x^{32} + 371008 x^{30} + 1582240 x^{28} + 5178240 x^{26} + 13147875 x^{24} + 26013000 x^{22} + 40060019 x^{20} + 47720380 x^{18} + 43459480 x^{16} + 29715200 x^{14} + 14855725 x^{12} + 5226012 x^{10} + 1221495 x^{8} + 172920 x^{6} + 12475 x^{4} + 300 x^{2} + 1 \)

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

Invariants

Degree:  $40$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[0, 20]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(10240000000000000000000000000000000000000000000000000000000000000000000000=2^{80}\cdot 5^{70}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $66.87$
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:  $2, 5$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(200=2^{3}\cdot 5^{2}\)
Dirichlet character group:    $\lbrace$$\chi_{200}(1,·)$, $\chi_{200}(131,·)$, $\chi_{200}(133,·)$, $\chi_{200}(7,·)$, $\chi_{200}(9,·)$, $\chi_{200}(11,·)$, $\chi_{200}(13,·)$, $\chi_{200}(143,·)$, $\chi_{200}(19,·)$, $\chi_{200}(23,·)$, $\chi_{200}(179,·)$, $\chi_{200}(157,·)$, $\chi_{200}(161,·)$, $\chi_{200}(37,·)$, $\chi_{200}(167,·)$, $\chi_{200}(129,·)$, $\chi_{200}(41,·)$, $\chi_{200}(171,·)$, $\chi_{200}(173,·)$, $\chi_{200}(47,·)$, $\chi_{200}(49,·)$, $\chi_{200}(51,·)$, $\chi_{200}(53,·)$, $\chi_{200}(183,·)$, $\chi_{200}(59,·)$, $\chi_{200}(63,·)$, $\chi_{200}(139,·)$, $\chi_{200}(197,·)$, $\chi_{200}(77,·)$, $\chi_{200}(81,·)$, $\chi_{200}(87,·)$, $\chi_{200}(89,·)$, $\chi_{200}(91,·)$, $\chi_{200}(93,·)$, $\chi_{200}(99,·)$, $\chi_{200}(103,·)$, $\chi_{200}(117,·)$, $\chi_{200}(169,·)$, $\chi_{200}(121,·)$, $\chi_{200}(127,·)$$\rbrace$
This is a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $a^{16}$, $a^{17}$, $a^{18}$, $a^{19}$, $a^{20}$, $a^{21}$, $a^{22}$, $a^{23}$, $a^{24}$, $a^{25}$, $a^{26}$, $a^{27}$, $a^{28}$, $a^{29}$, $a^{30}$, $a^{31}$, $a^{32}$, $a^{33}$, $a^{34}$, $a^{35}$, $a^{36}$, $a^{37}$, $a^{38}$, $a^{39}$

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

Class group and class number

$C_{542102}$, which has order $542102$ (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:  $19$
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:  \( 144312257071955.8 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_2\times C_{20}$ (as 40T2):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
An abelian group of order 40
The 40 conjugacy class representatives for $C_2\times C_{20}$
Character table for $C_2\times C_{20}$ is not computed

Intermediate fields

\(\Q(\sqrt{-2}) \), \(\Q(\sqrt{5}) \), \(\Q(\sqrt{-10}) \), \(\Q(\sqrt{-2}, \sqrt{5})\), 4.0.8000.2, \(\Q(\zeta_{20})^+\), 5.5.390625.1, 8.0.1024000000.1, 10.0.5000000000000000.1, \(\Q(\zeta_{25})^+\), 10.0.25000000000000000.1, 20.0.625000000000000000000000000000000.1, 20.0.3125000000000000000000000000000000.1, \(\Q(\zeta_{100})^+\)

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

Frobenius cycle types

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59
Cycle type R $20^{2}$ R ${\href{/LocalNumberField/7.4.0.1}{4} }^{10}$ ${\href{/LocalNumberField/11.10.0.1}{10} }^{4}$ $20^{2}$ $20^{2}$ ${\href{/LocalNumberField/19.5.0.1}{5} }^{8}$ $20^{2}$ ${\href{/LocalNumberField/29.10.0.1}{10} }^{4}$ ${\href{/LocalNumberField/31.10.0.1}{10} }^{4}$ $20^{2}$ ${\href{/LocalNumberField/41.5.0.1}{5} }^{8}$ ${\href{/LocalNumberField/43.4.0.1}{4} }^{10}$ $20^{2}$ $20^{2}$ ${\href{/LocalNumberField/59.5.0.1}{5} }^{8}$

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
2Data not computed
5Data not computed