Properties

Label 20.20.171...125.1
Degree $20$
Signature $(20, 0)$
Discriminant $1.719\times 10^{29}$
Root discriminant \(28.96\)
Ramified primes $3,5$
Class number $1$ (GRH)
Class group trivial (GRH)
Galois group $C_{20}$ (as 20T1)

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Normalized defining polynomial

Copy content comment:Define the number field
 
Copy content sage:x = polygen(QQ); K.<a> = NumberField(x^20 - 20*x^18 + 170*x^16 - x^15 - 800*x^14 + 15*x^13 + 2275*x^12 - 90*x^11 - 4004*x^10 + 275*x^9 + 4290*x^8 - 450*x^7 - 2640*x^6 + 379*x^5 + 825*x^4 - 145*x^3 - 100*x^2 + 20*x + 1)
 
Copy content gp:K = bnfinit(y^20 - 20*y^18 + 170*y^16 - y^15 - 800*y^14 + 15*y^13 + 2275*y^12 - 90*y^11 - 4004*y^10 + 275*y^9 + 4290*y^8 - 450*y^7 - 2640*y^6 + 379*y^5 + 825*y^4 - 145*y^3 - 100*y^2 + 20*y + 1, 1)
 
Copy content magma:R<x> := PolynomialRing(Rationals()); K<a> := NumberField(x^20 - 20*x^18 + 170*x^16 - x^15 - 800*x^14 + 15*x^13 + 2275*x^12 - 90*x^11 - 4004*x^10 + 275*x^9 + 4290*x^8 - 450*x^7 - 2640*x^6 + 379*x^5 + 825*x^4 - 145*x^3 - 100*x^2 + 20*x + 1);
 
Copy content oscar:Qx, x = polynomial_ring(QQ); K, a = number_field(x^20 - 20*x^18 + 170*x^16 - x^15 - 800*x^14 + 15*x^13 + 2275*x^12 - 90*x^11 - 4004*x^10 + 275*x^9 + 4290*x^8 - 450*x^7 - 2640*x^6 + 379*x^5 + 825*x^4 - 145*x^3 - 100*x^2 + 20*x + 1)
 

\( x^{20} - 20 x^{18} + 170 x^{16} - x^{15} - 800 x^{14} + 15 x^{13} + 2275 x^{12} - 90 x^{11} - 4004 x^{10} + \cdots + 1 \) 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:  $20$
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:  $(20, 0)$
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:   \(171855208463966846466064453125\) \(\medspace = 3^{10}\cdot 5^{35}\) 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:  \(28.96\)
Copy content comment:Root discriminant
 
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:OK = ring_of_integers(K); (1.0 * abs(discriminant(OK)))^(1/degree(K))
 
Galois root discriminant:  $3^{1/2}5^{7/4}\approx 28.957304632206725$
Ramified primes:   \(3\), \(5\) 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:  \(\Q(\sqrt{5}) \)
$\Aut(K/\Q)$ $=$ $\Gal(K/\Q)$:   $C_{20}$
Copy content comment:Automorphisms
 
Copy content sage:K.automorphisms()
 
Copy content magma:Automorphisms(K);
 
Copy content oscar:automorphism_group(K)
 
This field is Galois and abelian over $\Q$.
Conductor:  \(75=3\cdot 5^{2}\)
Dirichlet character group:    $\lbrace$$\chi_{75}(64,·)$, $\chi_{75}(1,·)$, $\chi_{75}(2,·)$, $\chi_{75}(4,·)$, $\chi_{75}(8,·)$, $\chi_{75}(16,·)$, $\chi_{75}(17,·)$, $\chi_{75}(19,·)$, $\chi_{75}(23,·)$, $\chi_{75}(68,·)$, $\chi_{75}(31,·)$, $\chi_{75}(32,·)$, $\chi_{75}(34,·)$, $\chi_{75}(38,·)$, $\chi_{75}(46,·)$, $\chi_{75}(47,·)$, $\chi_{75}(49,·)$, $\chi_{75}(53,·)$, $\chi_{75}(61,·)$, $\chi_{75}(62,·)$$\rbrace$
This is not a CM field.
This field has no CM subfields.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $a^{16}$, $a^{17}$, $a^{18}$, $a^{19}$ 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:  Yes
Index:  $1$
Inessential primes:  None

Class group and class number

Ideal class group:  Trivial group, which has order $1$ (assuming GRH)
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:  $C_{2}$, which has order $2$ (assuming GRH)
Copy content comment:Narrow class group
 
Copy content sage:K.narrow_class_group().invariants()
 
Copy content gp:bnfnarrow(K)
 
Copy content magma:NarrowClassGroup(K);
 

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:  $19$
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:   \( -1 \)  (order $2$) 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:   $a^{15}-15a^{13}+90a^{11}-275a^{9}+450a^{7}-378a^{5}+140a^{3}-15a$, $a^{9}-9a^{7}+27a^{5}-30a^{3}+9a$, $a^{19}-19a^{17}-a^{16}+152a^{15}+15a^{14}-665a^{13}-90a^{12}+1729a^{11}+275a^{10}-2717a^{9}-450a^{8}+2508a^{7}+379a^{6}-1254a^{5}-145a^{4}+285a^{3}+20a^{2}-20a$, $a^{14}-14a^{12}+a^{11}+77a^{10}-11a^{9}-210a^{8}+44a^{7}+294a^{6}-77a^{5}-196a^{4}+55a^{3}+49a^{2}-11a-2$, $a^{17}-16a^{15}-a^{14}+104a^{13}+13a^{12}-353a^{11}-65a^{10}+671a^{9}+157a^{8}-716a^{7}-189a^{6}+413a^{5}+105a^{4}-119a^{3}-20a^{2}+13a$, $a^{3}-3a$, $a^{18}-18a^{16}+a^{15}+135a^{14}-15a^{13}-545a^{12}+90a^{11}+1275a^{10}-274a^{9}-1728a^{8}+441a^{7}+1275a^{6}-351a^{5}-441a^{4}+111a^{3}+54a^{2}-9a-1$, $a^{12}-12a^{10}+54a^{8}-112a^{6}+105a^{4}-36a^{2}+2$, $a^{17}-17a^{15}+119a^{13}-a^{12}-442a^{11}+12a^{10}+936a^{9}-53a^{8}-1131a^{7}+104a^{6}+741a^{5}-85a^{4}-235a^{3}+20a^{2}+29a+1$, $a^{18}-19a^{16}+a^{15}+151a^{14}-16a^{13}-649a^{12}+103a^{11}+1626a^{10}-339a^{9}-2378a^{8}+596a^{7}+1913a^{6}-527a^{5}-734a^{4}+194a^{3}+105a^{2}-24a-2$, $a^{16}-16a^{14}+104a^{12}-352a^{10}+660a^{8}-672a^{6}+336a^{4}-64a^{2}+2$, $a^{17}-17a^{15}+119a^{13}-442a^{11}+935a^{9}-1122a^{7}+714a^{5}-204a^{3}+17a$, $a^{4}-4a^{2}+2$, $a^{12}-a^{11}-11a^{10}+10a^{9}+45a^{8}-36a^{7}-84a^{6}+56a^{5}+70a^{4}-35a^{3}-21a^{2}+6a+1$, $a^{16}-16a^{14}+104a^{12}-352a^{10}+661a^{8}-680a^{6}+356a^{4}-80a^{2}+5$, $a$, $a^{10}-10a^{8}+35a^{6}-50a^{4}+25a^{2}-3$, $a^{2}-2$, $a^{18}-a^{17}-18a^{16}+17a^{15}+135a^{14}-120a^{13}-546a^{12}+455a^{11}+1287a^{10}-1000a^{9}-1782a^{8}+1279a^{7}+1386a^{6}-903a^{5}-540a^{4}+310a^{3}+80a^{2}-40a$ Copy content Toggle raw display (assuming GRH)
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:  \( 122630529.842 \) (assuming GRH)
Copy content comment:Regulator
 
Copy content sage:K.regulator()
 
Copy content gp:K.reg
 
Copy content magma:Regulator(K);
 
Copy content oscar:regulator(K)
 
Unit signature rank:  \( 19 \) (assuming GRH)

Class number formula

\[ \begin{aligned}\lim_{s\to 1} (s-1)\zeta_K(s) =\mathstrut & \frac{2^{r_1}\cdot (2\pi)^{r_2}\cdot R\cdot h}{w\cdot\sqrt{|D|}}\cr \approx\mathstrut &\frac{2^{20}\cdot(2\pi)^{0}\cdot 122630529.842 \cdot 1}{2\cdot\sqrt{171855208463966846466064453125}}\cr\approx \mathstrut & 0.155091205907 \end{aligned}\] (assuming GRH)

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^20 - 20*x^18 + 170*x^16 - x^15 - 800*x^14 + 15*x^13 + 2275*x^12 - 90*x^11 - 4004*x^10 + 275*x^9 + 4290*x^8 - 450*x^7 - 2640*x^6 + 379*x^5 + 825*x^4 - 145*x^3 - 100*x^2 + 20*x + 1) 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^20 - 20*x^18 + 170*x^16 - x^15 - 800*x^14 + 15*x^13 + 2275*x^12 - 90*x^11 - 4004*x^10 + 275*x^9 + 4290*x^8 - 450*x^7 - 2640*x^6 + 379*x^5 + 825*x^4 - 145*x^3 - 100*x^2 + 20*x + 1, 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^20 - 20*x^18 + 170*x^16 - x^15 - 800*x^14 + 15*x^13 + 2275*x^12 - 90*x^11 - 4004*x^10 + 275*x^9 + 4290*x^8 - 450*x^7 - 2640*x^6 + 379*x^5 + 825*x^4 - 145*x^3 - 100*x^2 + 20*x + 1); 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 = polynomial_ring(QQ); K, a = number_field(x^20 - 20*x^18 + 170*x^16 - x^15 - 800*x^14 + 15*x^13 + 2275*x^12 - 90*x^11 - 4004*x^10 + 275*x^9 + 4290*x^8 - 450*x^7 - 2640*x^6 + 379*x^5 + 825*x^4 - 145*x^3 - 100*x^2 + 20*x + 1); 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

$C_{20}$ (as 20T1):

Copy content comment:Galois group
 
Copy content sage:K.galois_group()
 
Copy content gp:polgalois(K.pol)
 
Copy content magma:G = GaloisGroup(K);
 
Copy content oscar:G, Gtx = galois_group(K); degree(K) > 1 ? (G, transitive_group_identification(G)) : (G, nothing)
 
A cyclic group of order 20
The 20 conjugacy class representatives for $C_{20}$
Character table for $C_{20}$

Intermediate fields

\(\Q(\sqrt{5}) \), \(\Q(\zeta_{15})^+\), 5.5.390625.1, \(\Q(\zeta_{25})^+\)

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(L)]
 
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 $20$ R R ${\href{/padicField/7.4.0.1}{4} }^{5}$ ${\href{/padicField/11.10.0.1}{10} }^{2}$ $20$ $20$ ${\href{/padicField/19.10.0.1}{10} }^{2}$ $20$ ${\href{/padicField/29.5.0.1}{5} }^{4}$ ${\href{/padicField/31.5.0.1}{5} }^{4}$ $20$ ${\href{/padicField/41.10.0.1}{10} }^{2}$ ${\href{/padicField/43.4.0.1}{4} }^{5}$ $20$ $20$ ${\href{/padicField/59.5.0.1}{5} }^{4}$

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
\(3\) Copy content Toggle raw display 3.10.2.10a1.1$x^{20} + 4 x^{16} + 4 x^{15} + 4 x^{14} + 4 x^{12} + 10 x^{11} + 16 x^{10} + 8 x^{9} + 4 x^{8} + 4 x^{7} + 12 x^{6} + 12 x^{5} + 8 x^{4} + x^{2} + 7 x + 4$$2$$10$$10$20T1$$[\ ]_{2}^{10}$$
\(5\) Copy content Toggle raw display 5.1.20.35a1.500$x^{20} + 5 x^{16} + 120$$20$$1$$35$20T1not computed

Spectrum of ring of integers

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