Normalized defining polynomial
\( x^{8} - 8 x^{6} + 20 x^{4} - 16 x^{2} - 124 \)
Invariants
| Degree: | $8$ | magma: Degree(K);
sage: K.degree()
gp: poldegree(K.pol)
| |
| Signature: | $[2, 3]$ | magma: Signature(K);
sage: K.signature()
gp: K.sign
| |
| Discriminant: | \(-124952510464=-\,2^{22}\cdot 31^{3}\) | magma: Discriminant(Integers(K));
sage: K.disc()
gp: K.disc
| |
| Root discriminant: | $24.38$ | 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: | $2, 31$ | magma: PrimeDivisors(Discriminant(Integers(K)));
sage: K.disc().support()
gp: factor(abs(K.disc))[,1]~
| |
| This field is not Galois over $\Q$. | |||
| This is not a CM field. | |||
Integral basis (with respect to field generator \(a\))
$1$, $a$, $a^{2}$, $a^{3}$, $\frac{1}{16} a^{4} + \frac{1}{4} a^{2} + \frac{1}{8}$, $\frac{1}{16} a^{5} + \frac{1}{4} a^{3} + \frac{1}{8} a$, $\frac{1}{32} a^{6} + \frac{1}{16} a^{2} - \frac{1}{4}$, $\frac{1}{32} a^{7} + \frac{1}{16} a^{3} - \frac{1}{4} a$
Class group and class number
Trivial group, which has order $1$
Unit group
| Rank: | $4$ | 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: | \( \frac{1}{8} a^{4} - \frac{1}{2} a^{2} + \frac{5}{4} \), \( \frac{1}{16} a^{4} + \frac{1}{4} a^{2} + \frac{1}{8} \), \( \frac{1}{16} a^{7} - \frac{1}{16} a^{6} - \frac{3}{8} a^{5} - \frac{1}{4} a^{4} + \frac{5}{8} a^{3} + \frac{7}{8} a^{2} + \frac{11}{4} a + 1 \), \( \frac{1}{4} a^{7} + \frac{1}{2} a^{6} - \frac{7}{8} a^{5} - \frac{5}{4} a^{4} + 3 a^{3} + 6 a^{2} + \frac{33}{4} a + \frac{33}{2} \) | magma: [K!f(g): g in Generators(UK)];
sage: UK.fundamental_units()
gp: K.fu
| |
| Regulator: | \( 595.966172184 \) | magma: Regulator(K);
sage: K.regulator()
gp: K.reg
|
Galois group
| A solvable group of order 16 |
| The 7 conjugacy class representatives for $QD_{16}$ |
| Character table for $QD_{16}$ |
Intermediate fields
| \(\Q(\sqrt{2}) \), 4.2.1984.1 |
Fields in the database are given up to isomorphism. Isomorphic intermediate fields are shown with their multiplicities.
Sibling fields
| Galois closure: | 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 | R | ${\href{/LocalNumberField/3.8.0.1}{8} }$ | ${\href{/LocalNumberField/5.4.0.1}{4} }^{2}$ | ${\href{/LocalNumberField/7.4.0.1}{4} }^{2}$ | ${\href{/LocalNumberField/11.8.0.1}{8} }$ | ${\href{/LocalNumberField/13.8.0.1}{8} }$ | ${\href{/LocalNumberField/17.2.0.1}{2} }^{3}{,}\,{\href{/LocalNumberField/17.1.0.1}{1} }^{2}$ | ${\href{/LocalNumberField/19.4.0.1}{4} }^{2}$ | ${\href{/LocalNumberField/23.2.0.1}{2} }^{3}{,}\,{\href{/LocalNumberField/23.1.0.1}{1} }^{2}$ | ${\href{/LocalNumberField/29.8.0.1}{8} }$ | R | ${\href{/LocalNumberField/37.8.0.1}{8} }$ | ${\href{/LocalNumberField/41.4.0.1}{4} }^{2}$ | ${\href{/LocalNumberField/43.8.0.1}{8} }$ | ${\href{/LocalNumberField/47.4.0.1}{4} }^{2}$ | ${\href{/LocalNumberField/53.8.0.1}{8} }$ | ${\href{/LocalNumberField/59.4.0.1}{4} }^{2}$ |
In the table, R denotes a ramified prime. Cycle lengths which are repeated in a cycle type are indicated by exponents.
Local algebras for ramified primes
| $p$ | Label | Polynomial | $e$ | $f$ | $c$ | Galois group | Slope content |
|---|---|---|---|---|---|---|---|
| $2$ | 2.4.11.3 | $x^{4} + 4 x^{2} + 18$ | $4$ | $1$ | $11$ | $C_4$ | $[3, 4]$ |
| 2.4.11.3 | $x^{4} + 4 x^{2} + 18$ | $4$ | $1$ | $11$ | $C_4$ | $[3, 4]$ | |
| $31$ | $\Q_{31}$ | $x + 7$ | $1$ | $1$ | $0$ | Trivial | $[\ ]$ |
| $\Q_{31}$ | $x + 7$ | $1$ | $1$ | $0$ | Trivial | $[\ ]$ | |
| 31.2.1.2 | $x^{2} + 217$ | $2$ | $1$ | $1$ | $C_2$ | $[\ ]_{2}$ | |
| 31.2.1.2 | $x^{2} + 217$ | $2$ | $1$ | $1$ | $C_2$ | $[\ ]_{2}$ | |
| 31.2.1.2 | $x^{2} + 217$ | $2$ | $1$ | $1$ | $C_2$ | $[\ ]_{2}$ |
Artin representations
| Label | Dimension | Conductor | Defining polynomial of Artin field | $G$ | Ind | $\chi(c)$ | |
|---|---|---|---|---|---|---|---|
| * | 1.1.1t1.1c1 | $1$ | $1$ | $x$ | $C_1$ | $1$ | $1$ |
| * | 1.2e3.2t1.1c1 | $1$ | $ 2^{3}$ | $x^{2} - 2$ | $C_2$ (as 2T1) | $1$ | $1$ |
| 1.31.2t1.1c1 | $1$ | $ 31 $ | $x^{2} - x + 8$ | $C_2$ (as 2T1) | $1$ | $-1$ | |
| 1.2e3_31.2t1.2c1 | $1$ | $ 2^{3} \cdot 31 $ | $x^{2} + 62$ | $C_2$ (as 2T1) | $1$ | $-1$ | |
| * | 2.2e3_31.4t3.2c1 | $2$ | $ 2^{3} \cdot 31 $ | $x^{4} - x^{3} + 4 x^{2} + 2 x + 4$ | $D_{4}$ (as 4T3) | $1$ | $0$ |
| * | 2.2e8_31.8t8.1c1 | $2$ | $ 2^{8} \cdot 31 $ | $x^{8} - 8 x^{6} + 20 x^{4} - 16 x^{2} - 124$ | $QD_{16}$ (as 8T8) | $0$ | $0$ |
| * | 2.2e8_31.8t8.1c2 | $2$ | $ 2^{8} \cdot 31 $ | $x^{8} - 8 x^{6} + 20 x^{4} - 16 x^{2} - 124$ | $QD_{16}$ (as 8T8) | $0$ | $0$ |