Properties

Label 20.0.16442223510...5625.1
Degree $20$
Signature $[0, 10]$
Discriminant $5^{34}\cdot 7^{10}$
Root discriminant $40.81$
Ramified primes $5, 7$
Class number $256$ (GRH)
Class group $[4, 4, 4, 4]$ (GRH)
Galois group $C_2\times C_{10}$ (as 20T3)

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magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1024, 2560, 32000, -28800, 172800, -63648, 238320, -42800, 173240, -15000, 74975, -2735, 20825, -265, 3750, -11, 435, 0, 30, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^20 + 30*x^18 + 435*x^16 - 11*x^15 + 3750*x^14 - 265*x^13 + 20825*x^12 - 2735*x^11 + 74975*x^10 - 15000*x^9 + 173240*x^8 - 42800*x^7 + 238320*x^6 - 63648*x^5 + 172800*x^4 - 28800*x^3 + 32000*x^2 + 2560*x + 1024)
 
gp: K = bnfinit(x^20 + 30*x^18 + 435*x^16 - 11*x^15 + 3750*x^14 - 265*x^13 + 20825*x^12 - 2735*x^11 + 74975*x^10 - 15000*x^9 + 173240*x^8 - 42800*x^7 + 238320*x^6 - 63648*x^5 + 172800*x^4 - 28800*x^3 + 32000*x^2 + 2560*x + 1024, 1)
 

Normalized defining polynomial

\( x^{20} + 30 x^{18} + 435 x^{16} - 11 x^{15} + 3750 x^{14} - 265 x^{13} + 20825 x^{12} - 2735 x^{11} + 74975 x^{10} - 15000 x^{9} + 173240 x^{8} - 42800 x^{7} + 238320 x^{6} - 63648 x^{5} + 172800 x^{4} - 28800 x^{3} + 32000 x^{2} + 2560 x + 1024 \)

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

Invariants

Degree:  $20$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[0, 10]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(164422235102392733097076416015625=5^{34}\cdot 7^{10}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $40.81$
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:  $5, 7$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(175=5^{2}\cdot 7\)
Dirichlet character group:    $\lbrace$$\chi_{175}(64,·)$, $\chi_{175}(1,·)$, $\chi_{175}(69,·)$, $\chi_{175}(6,·)$, $\chi_{175}(71,·)$, $\chi_{175}(139,·)$, $\chi_{175}(76,·)$, $\chi_{175}(141,·)$, $\chi_{175}(146,·)$, $\chi_{175}(29,·)$, $\chi_{175}(34,·)$, $\chi_{175}(99,·)$, $\chi_{175}(36,·)$, $\chi_{175}(134,·)$, $\chi_{175}(104,·)$, $\chi_{175}(41,·)$, $\chi_{175}(106,·)$, $\chi_{175}(174,·)$, $\chi_{175}(111,·)$, $\chi_{175}(169,·)$$\rbrace$
This is a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $\frac{1}{2} a^{11} - \frac{1}{2} a^{7} - \frac{1}{2} a^{6} - \frac{1}{2} a^{4} - \frac{1}{2} a^{3} - \frac{1}{2} a^{2} - \frac{1}{2} a$, $\frac{1}{4} a^{12} - \frac{1}{2} a^{10} - \frac{1}{4} a^{8} + \frac{1}{4} a^{7} - \frac{1}{2} a^{6} - \frac{1}{4} a^{5} + \frac{1}{4} a^{4} + \frac{1}{4} a^{3} - \frac{1}{4} a^{2}$, $\frac{1}{8} a^{13} - \frac{1}{4} a^{11} + \frac{3}{8} a^{9} - \frac{3}{8} a^{8} - \frac{1}{4} a^{7} - \frac{1}{8} a^{6} + \frac{1}{8} a^{5} + \frac{1}{8} a^{4} - \frac{1}{8} a^{3}$, $\frac{1}{16} a^{14} - \frac{1}{8} a^{12} + \frac{3}{16} a^{10} + \frac{5}{16} a^{9} + \frac{3}{8} a^{8} + \frac{7}{16} a^{7} - \frac{7}{16} a^{6} + \frac{1}{16} a^{5} - \frac{1}{16} a^{4} - \frac{1}{2} a^{3} - \frac{1}{2} a^{2}$, $\frac{1}{32} a^{15} - \frac{1}{16} a^{13} + \frac{3}{32} a^{11} - \frac{11}{32} a^{10} + \frac{3}{16} a^{9} - \frac{9}{32} a^{8} + \frac{9}{32} a^{7} + \frac{1}{32} a^{6} - \frac{1}{32} a^{5} - \frac{1}{4} a^{4} + \frac{1}{4} a^{3}$, $\frac{1}{64} a^{16} - \frac{1}{32} a^{14} + \frac{3}{64} a^{12} - \frac{11}{64} a^{11} - \frac{13}{32} a^{10} + \frac{23}{64} a^{9} + \frac{9}{64} a^{8} + \frac{1}{64} a^{7} + \frac{31}{64} a^{6} - \frac{1}{8} a^{5} - \frac{3}{8} a^{4} - \frac{1}{2} a^{3} - \frac{1}{2} a^{2} - \frac{1}{2} a$, $\frac{1}{128} a^{17} - \frac{1}{64} a^{15} + \frac{3}{128} a^{13} - \frac{11}{128} a^{12} - \frac{13}{64} a^{11} - \frac{41}{128} a^{10} - \frac{55}{128} a^{9} - \frac{63}{128} a^{8} - \frac{33}{128} a^{7} - \frac{1}{16} a^{6} - \frac{3}{16} a^{5} + \frac{1}{4} a^{4} + \frac{1}{4} a^{3} + \frac{1}{4} a^{2} - \frac{1}{2} a$, $\frac{1}{38656} a^{18} - \frac{11}{9664} a^{17} + \frac{85}{19328} a^{16} + \frac{17}{2416} a^{15} - \frac{357}{38656} a^{14} - \frac{1695}{38656} a^{13} - \frac{233}{19328} a^{12} + \frac{9427}{38656} a^{11} - \frac{7611}{38656} a^{10} - \frac{823}{38656} a^{9} - \frac{1529}{38656} a^{8} - \frac{2133}{4832} a^{7} + \frac{2777}{9664} a^{6} - \frac{761}{4832} a^{5} + \frac{767}{2416} a^{4} - \frac{157}{604} a^{3} - \frac{2}{151} a^{2} + \frac{27}{151} a - \frac{38}{151}$, $\frac{1}{29317056377047323534965427990016} a^{19} + \frac{116287832883067636192753635}{14658528188523661767482713995008} a^{18} - \frac{47519750953249340144151147983}{14658528188523661767482713995008} a^{17} - \frac{9125333208894981157810533657}{7329264094261830883741356997504} a^{16} + \frac{215644833076811151846496236459}{29317056377047323534965427990016} a^{15} - \frac{687635327532069781048445878153}{29317056377047323534965427990016} a^{14} + \frac{11074425076886542504964237651}{1832316023565457720935339249376} a^{13} - \frac{2801539483297529393290296536089}{29317056377047323534965427990016} a^{12} - \frac{6819036550099762160637523191805}{29317056377047323534965427990016} a^{11} - \frac{6603318871590759902366637395501}{29317056377047323534965427990016} a^{10} - \frac{10377461095959016213927154511263}{29317056377047323534965427990016} a^{9} - \frac{3583111321607642088603252303129}{14658528188523661767482713995008} a^{8} + \frac{3308080390916865441669819604155}{7329264094261830883741356997504} a^{7} - \frac{1221045298687900354990066780361}{3664632047130915441870678498752} a^{6} + \frac{239124181401389628723774818269}{1832316023565457720935339249376} a^{5} - \frac{421778264695122252693282485319}{916158011782728860467669624688} a^{4} + \frac{113534101401828514441400276225}{229039502945682215116917406172} a^{3} - \frac{13729286036256328330940188693}{114519751472841107558458703086} a^{2} - \frac{51414517201724033813935762467}{114519751472841107558458703086} a + \frac{13903602718528357874238958125}{57259875736420553779229351543}$

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

Class group and class number

$C_{4}\times C_{4}\times C_{4}\times C_{4}$, which has order $256$ (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:  $9$
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:  \( 161406.837641 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_2\times C_{10}$ (as 20T3):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
An abelian group of order 20
The 20 conjugacy class representatives for $C_2\times C_{10}$
Character table for $C_2\times C_{10}$

Intermediate fields

\(\Q(\sqrt{5}) \), \(\Q(\sqrt{-35}) \), \(\Q(\sqrt{-7}) \), \(\Q(\sqrt{5}, \sqrt{-7})\), 5.5.390625.1, \(\Q(\zeta_{25})^+\), 10.0.12822723388671875.1, 10.0.2564544677734375.1

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 ${\href{/LocalNumberField/2.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/3.10.0.1}{10} }^{2}$ R R ${\href{/LocalNumberField/11.5.0.1}{5} }^{4}$ ${\href{/LocalNumberField/13.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/17.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/19.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/23.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/29.5.0.1}{5} }^{4}$ ${\href{/LocalNumberField/31.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/37.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/41.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/43.2.0.1}{2} }^{10}$ ${\href{/LocalNumberField/47.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/53.10.0.1}{10} }^{2}$ ${\href{/LocalNumberField/59.10.0.1}{10} }^{2}$

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
5Data not computed
$7$7.4.2.1$x^{4} + 35 x^{2} + 441$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
7.4.2.1$x^{4} + 35 x^{2} + 441$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
7.4.2.1$x^{4} + 35 x^{2} + 441$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
7.4.2.1$x^{4} + 35 x^{2} + 441$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$
7.4.2.1$x^{4} + 35 x^{2} + 441$$2$$2$$2$$C_2^2$$[\ ]_{2}^{2}$