Properties

Label 31.1.187...144.1
Degree $31$
Signature $[1, 15]$
Discriminant $-1.877\times 10^{55}$
Root discriminant \(60.68\)
Ramified primes see page
Class number $1$ (GRH)
Class group trivial (GRH)
Galois group $S_{31}$ (as 31T12)

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Show commands: Magma / Oscar / PariGP / SageMath

Normalized defining polynomial

sage: x = polygen(QQ); K.<a> = NumberField(x^31 + 2*x - 2)
 
gp: K = bnfinit(y^31 + 2*y - 2, 1)
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(x^31 + 2*x - 2);
 
oscar: Qx, x = PolynomialRing(QQ); K, a = NumberField(x^31 + 2*x - 2)
 

\( x^{31} + 2x - 2 \) Copy content Toggle raw display

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

Invariants

Degree:  $31$
sage: K.degree()
 
gp: poldegree(K.pol)
 
magma: Degree(K);
 
oscar: degree(K)
 
Signature:  $[1, 15]$
sage: K.signature()
 
gp: K.sign
 
magma: Signature(K);
 
oscar: signature(K)
 
Discriminant:   \(-18770034004737848533180532351835033630345588173537542144\) \(\medspace = -\,2^{30}\cdot 11\cdot 1489\cdot 1499\cdot 23334601\cdot 28850169461\cdot 1057614572100224186051\) Copy content Toggle raw display
sage: K.disc()
 
gp: K.disc
 
magma: OK := Integers(K); Discriminant(OK);
 
oscar: OK = ring_of_integers(K); discriminant(OK)
 
Root discriminant:  \(60.68\)
sage: (K.disc().abs())^(1./K.degree())
 
gp: abs(K.disc)^(1/poldegree(K.pol))
 
magma: Abs(Discriminant(OK))^(1/Degree(K));
 
oscar: (1.0 * dK)^(1/degree(K))
 
Galois root discriminant:  $2^{30/31}11^{1/2}1489^{1/2}1499^{1/2}23334601^{1/2}28850169461^{1/2}1057614572100224186051^{1/2}\approx 2.5858417634744722e+23$
Ramified primes:   \(2\), \(11\), \(1489\), \(1499\), \(23334601\), \(28850169461\), \(1057614572100224186051\) Copy content Toggle raw display
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
magma: PrimeDivisors(Discriminant(OK));
 
oscar: prime_divisors(discriminant((OK)))
 
Discriminant root field:  $\Q(\sqrt{-17480\!\cdots\!34431}$)
$\card{ \Aut(K/\Q) }$:  $1$
sage: K.automorphisms()
 
magma: Automorphisms(K);
 
oscar: automorphisms(K)
 
This field is not Galois over $\Q$.
This is not a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $a^{16}$, $a^{17}$, $a^{18}$, $a^{19}$, $a^{20}$, $a^{21}$, $a^{22}$, $a^{23}$, $a^{24}$, $a^{25}$, $a^{26}$, $a^{27}$, $a^{28}$, $a^{29}$, $a^{30}$ Copy content Toggle raw display

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

Monogenic:  Yes
Index:  $1$
Inessential primes:  None

Class group and class number

Trivial group, which has order $1$ (assuming GRH)

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

Unit group

sage: UK = K.unit_group()
 
magma: UK, fUK := UnitGroup(K);
 
oscar: UK, fUK = unit_group(OK)
 
Rank:  $15$
sage: UK.rank()
 
gp: K.fu
 
magma: UnitRank(K);
 
oscar: rank(UK)
 
Torsion generator:   \( -1 \)  (order $2$) Copy content Toggle raw display
sage: UK.torsion_generator()
 
gp: K.tu[2]
 
magma: K!f(TU.1) where TU,f is TorsionUnitGroup(K);
 
oscar: torsion_units_generator(OK)
 
Fundamental units:   $a-1$, $a^{21}-a^{12}+a^{11}-a^{2}+1$, $a^{29}-a^{25}-a^{22}+a^{18}-a^{17}-2a^{16}+a^{13}+a^{12}-2a^{11}+2a^{9}-a^{8}-a^{7}+2a^{4}-a^{2}+2a-1$, $2a^{30}+a^{29}+a^{28}+2a^{27}+2a^{25}+a^{23}+a^{22}-a^{21}+2a^{20}-2a^{19}+2a^{18}-a^{17}+a^{15}-a^{14}+2a^{13}-a^{12}+a^{11}+a^{10}-a^{9}+3a^{8}-3a^{7}+3a^{6}-a^{5}+2a^{3}-3a^{2}+4a+1$, $a^{30}+2a^{29}+a^{28}-a^{25}-a^{24}+a^{22}+a^{20}-a^{18}-a^{17}-a^{15}+a^{14}+a^{13}-a^{11}-2a^{9}-a^{8}+a^{7}+a^{6}+a^{5}+2a^{4}-2a^{2}-a+1$, $a^{29}+a^{24}-a^{22}+a^{18}+a^{16}+a^{15}-2a^{14}+2a^{12}-a^{11}-a^{10}+a^{9}-a^{6}+a^{5}+3a^{4}-2a^{3}-2a^{2}+2a-1$, $a^{30}+a^{29}+a^{28}+a^{27}+a^{26}+2a^{25}+2a^{24}+a^{23}+a^{22}+a^{21}-a^{19}-a^{16}-a^{13}-2a^{12}-a^{11}-a^{9}+a^{7}-a^{5}-2a^{2}+3$, $a^{28}+a^{27}+2a^{26}+a^{25}+2a^{20}+a^{18}-a^{17}-a^{16}+a^{15}+2a^{13}-a^{10}+3a^{7}-3a^{3}+3a^{2}-2a+3$, $6a^{30}+3a^{29}-a^{28}-4a^{27}-6a^{26}-6a^{25}-4a^{24}-a^{23}+2a^{22}+4a^{21}+5a^{20}+4a^{19}+2a^{18}-a^{17}-3a^{16}-5a^{15}-5a^{14}-4a^{13}-a^{12}+a^{11}+4a^{10}+5a^{9}+5a^{8}+2a^{7}-4a^{5}-6a^{4}-7a^{3}-4a^{2}-2a+15$, $a^{30}+a^{29}-2a^{27}-3a^{26}-2a^{25}+a^{22}+2a^{21}+a^{20}-2a^{19}-3a^{18}-2a^{17}-a^{16}+a^{15}+2a^{14}+2a^{13}-2a^{10}-4a^{9}-2a^{8}+2a^{7}+3a^{6}+a^{5}+a^{4}-2a^{2}-4a+1$, $a^{29}-a^{28}-2a^{27}+2a^{23}-2a^{21}+3a^{17}+a^{16}-2a^{15}-a^{13}+3a^{11}+a^{10}-a^{9}-a^{8}-2a^{7}+a^{6}+a^{5}+2a^{4}+a^{3}-3a^{2}-a+1$, $2a^{30}+3a^{29}+2a^{28}+a^{27}-a^{25}-a^{24}-a^{23}-2a^{22}-a^{21}+a^{20}+a^{19}+2a^{18}+3a^{17}+2a^{16}-a^{14}-2a^{13}-3a^{12}-a^{9}+2a^{8}+2a^{7}+a^{6}+2a^{5}+2a^{4}-a^{3}-3a^{2}-a+1$, $a^{30}-a^{29}-2a^{28}-a^{27}-2a^{25}-4a^{24}-3a^{23}-a^{22}-2a^{21}-4a^{20}-4a^{19}-2a^{18}-2a^{16}-4a^{15}-2a^{14}+a^{13}+a^{12}-2a^{11}-2a^{10}+a^{9}+3a^{8}+a^{7}-2a^{6}+4a^{4}+4a^{3}-a^{2}-2a+5$, $5a^{30}+6a^{29}+5a^{28}+6a^{27}+4a^{26}+5a^{25}+4a^{24}+4a^{23}+4a^{22}+3a^{21}+2a^{20}+a^{19}+a^{18}-a^{17}-a^{16}-2a^{14}-a^{13}-3a^{12}-a^{11}-5a^{10}-a^{9}-5a^{8}-a^{7}-3a^{6}-a^{5}-3a^{4}-a^{3}-a^{2}-4a+11$, $a^{30}-a^{29}+a^{28}-2a^{27}-a^{26}+a^{25}-3a^{24}-a^{22}-2a^{21}+2a^{20}-2a^{19}+2a^{18}+a^{17}-2a^{16}+4a^{15}-a^{14}+3a^{12}-2a^{11}+2a^{10}-2a^{9}-3a^{8}+4a^{7}-5a^{6}+a^{5}+a^{4}-5a^{3}+5a^{2}-3a+3$ Copy content Toggle raw display (assuming GRH)
sage: UK.fundamental_units()
 
gp: K.fu
 
magma: [K|fUK(g): g in Generators(UK)];
 
oscar: [K(fUK(a)) for a in gens(UK)]
 
Regulator:  \( 5116384966428125.0 \) (assuming GRH)
sage: K.regulator()
 
gp: K.reg
 
magma: Regulator(K);
 
oscar: regulator(K)
 

Class number formula

\[ \begin{aligned}\lim_{s\to 1} (s-1)\zeta_K(s) =\mathstrut & \frac{2^{r_1}\cdot (2\pi)^{r_2}\cdot R\cdot h}{w\cdot\sqrt{|D|}}\cr \approx\mathstrut &\frac{2^{1}\cdot(2\pi)^{15}\cdot 5116384966428125.0 \cdot 1}{2\cdot\sqrt{18770034004737848533180532351835033630345588173537542144}}\cr\approx \mathstrut & 1.10899275730712 \end{aligned}\] (assuming GRH)

# self-contained SageMath code snippet to compute the analytic class number formula
 
x = polygen(QQ); K.<a> = NumberField(x^31 + 2*x - 2)
 
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))))
 
# self-contained Pari/GP code snippet to compute the analytic class number formula
 
K = bnfinit(x^31 + 2*x - 2, 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)))]
 
/* self-contained Magma code snippet to compute the analytic class number formula */
 
Qx<x> := PolynomialRing(QQ); K<a> := NumberField(x^31 + 2*x - 2);
 
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)));
 
# self-contained Oscar code snippet to compute the analytic class number formula
 
Qx, x = PolynomialRing(QQ); K, a = NumberField(x^31 + 2*x - 2);
 
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

$S_{31}$ (as 31T12):

sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
magma: G = GaloisGroup(K);
 
oscar: G, Gtx = galois_group(K); G, transitive_group_identification(G)
 
A non-solvable group of order 8222838654177922817725562880000000
The 6842 conjugacy class representatives for $S_{31}$ are not computed
Character table for $S_{31}$ is not computed

Intermediate fields

The extension is primitive: there are no intermediate fields between this field and $\Q$.
sage: K.subfields()[1:-1]
 
gp: L = nfsubfields(K); L[2..length(b)]
 
magma: L := Subfields(K); L[2..#L];
 
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 $29{,}\,{\href{/padicField/3.2.0.1}{2} }$ $20{,}\,{\href{/padicField/5.5.0.1}{5} }{,}\,{\href{/padicField/5.4.0.1}{4} }{,}\,{\href{/padicField/5.1.0.1}{1} }^{2}$ ${\href{/padicField/7.11.0.1}{11} }{,}\,{\href{/padicField/7.9.0.1}{9} }{,}\,{\href{/padicField/7.7.0.1}{7} }{,}\,{\href{/padicField/7.3.0.1}{3} }{,}\,{\href{/padicField/7.1.0.1}{1} }$ R $16{,}\,{\href{/padicField/13.6.0.1}{6} }^{2}{,}\,{\href{/padicField/13.2.0.1}{2} }{,}\,{\href{/padicField/13.1.0.1}{1} }$ $29{,}\,{\href{/padicField/17.1.0.1}{1} }^{2}$ ${\href{/padicField/19.13.0.1}{13} }{,}\,{\href{/padicField/19.8.0.1}{8} }^{2}{,}\,{\href{/padicField/19.1.0.1}{1} }^{2}$ $24{,}\,{\href{/padicField/23.4.0.1}{4} }{,}\,{\href{/padicField/23.1.0.1}{1} }^{3}$ $20{,}\,{\href{/padicField/29.11.0.1}{11} }$ ${\href{/padicField/31.10.0.1}{10} }^{3}{,}\,{\href{/padicField/31.1.0.1}{1} }$ ${\href{/padicField/37.12.0.1}{12} }^{2}{,}\,{\href{/padicField/37.7.0.1}{7} }$ $18{,}\,{\href{/padicField/41.6.0.1}{6} }{,}\,{\href{/padicField/41.3.0.1}{3} }{,}\,{\href{/padicField/41.2.0.1}{2} }{,}\,{\href{/padicField/41.1.0.1}{1} }^{2}$ ${\href{/padicField/43.10.0.1}{10} }{,}\,{\href{/padicField/43.8.0.1}{8} }{,}\,{\href{/padicField/43.6.0.1}{6} }{,}\,{\href{/padicField/43.4.0.1}{4} }{,}\,{\href{/padicField/43.1.0.1}{1} }^{3}$ $28{,}\,{\href{/padicField/47.2.0.1}{2} }{,}\,{\href{/padicField/47.1.0.1}{1} }$ $20{,}\,{\href{/padicField/53.10.0.1}{10} }{,}\,{\href{/padicField/53.1.0.1}{1} }$ $15{,}\,{\href{/padicField/59.9.0.1}{9} }{,}\,{\href{/padicField/59.5.0.1}{5} }{,}\,{\href{/padicField/59.2.0.1}{2} }$

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

# to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$ for $p=7$ in Sage:
 
p = 7; [(e, pr.norm().valuation(p)) for pr,e in K.factor(p)]
 
\\ to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$ for $p=7$ in Pari:
 
p = 7; pfac = idealprimedec(K, p); vector(length(pfac), j, [pfac[j][3], pfac[j][4]])
 
// to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$ for $p=7 in Magma:
 
p := 7; [<pr[2], Valuation(Norm(pr[1]), p)> : pr in Factorization(p*Integers(K))];
 
# to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$ 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 Deg $31$$31$$1$$30$
\(11\) Copy content Toggle raw display 11.2.1.2$x^{2} + 11$$2$$1$$1$$C_2$$[\ ]_{2}$
11.3.0.1$x^{3} + 2 x + 9$$1$$3$$0$$C_3$$[\ ]^{3}$
11.12.0.1$x^{12} + x^{8} + x^{7} + 4 x^{6} + 2 x^{5} + 5 x^{4} + 5 x^{3} + 6 x^{2} + 5 x + 2$$1$$12$$0$$C_{12}$$[\ ]^{12}$
11.14.0.1$x^{14} + 2 x^{7} + 9 x^{6} + 6 x^{5} + 4 x^{4} + 8 x^{3} + 6 x^{2} + 10 x + 2$$1$$14$$0$$C_{14}$$[\ ]^{14}$
\(1489\) Copy content Toggle raw display $\Q_{1489}$$x$$1$$1$$0$Trivial$[\ ]$
Deg $2$$2$$1$$1$$C_2$$[\ ]_{2}$
Deg $3$$1$$3$$0$$C_3$$[\ ]^{3}$
Deg $3$$1$$3$$0$$C_3$$[\ ]^{3}$
Deg $10$$1$$10$$0$$C_{10}$$[\ ]^{10}$
Deg $12$$1$$12$$0$$C_{12}$$[\ ]^{12}$
\(1499\) Copy content Toggle raw display $\Q_{1499}$$x$$1$$1$$0$Trivial$[\ ]$
$\Q_{1499}$$x$$1$$1$$0$Trivial$[\ ]$
Deg $2$$2$$1$$1$$C_2$$[\ ]_{2}$
Deg $27$$1$$27$$0$$C_{27}$$[\ ]^{27}$
\(23334601\) Copy content Toggle raw display $\Q_{23334601}$$x$$1$$1$$0$Trivial$[\ ]$
$\Q_{23334601}$$x$$1$$1$$0$Trivial$[\ ]$
$\Q_{23334601}$$x$$1$$1$$0$Trivial$[\ ]$
Deg $2$$2$$1$$1$$C_2$$[\ ]_{2}$
Deg $7$$1$$7$$0$$C_7$$[\ ]^{7}$
Deg $19$$1$$19$$0$$C_{19}$$[\ ]^{19}$
\(28850169461\) Copy content Toggle raw display $\Q_{28850169461}$$x$$1$$1$$0$Trivial$[\ ]$
Deg $2$$2$$1$$1$$C_2$$[\ ]_{2}$
Deg $6$$1$$6$$0$$C_6$$[\ ]^{6}$
Deg $9$$1$$9$$0$$C_9$$[\ ]^{9}$
Deg $13$$1$$13$$0$$C_{13}$$[\ ]^{13}$
\(105\!\cdots\!051\) Copy content Toggle raw display $\Q_{10\!\cdots\!51}$$x$$1$$1$$0$Trivial$[\ ]$
Deg $2$$1$$2$$0$$C_2$$[\ ]^{2}$
Deg $2$$1$$2$$0$$C_2$$[\ ]^{2}$
Deg $2$$2$$1$$1$$C_2$$[\ ]_{2}$
Deg $3$$1$$3$$0$$C_3$$[\ ]^{3}$
Deg $5$$1$$5$$0$$C_5$$[\ ]^{5}$
Deg $8$$1$$8$$0$$C_8$$[\ ]^{8}$
Deg $8$$1$$8$$0$$C_8$$[\ ]^{8}$