Defining polynomial
|
\(x^{8} + 2 x^{6} + 4 x + 2\)
|
Invariants
| Base field: | $\Q_{2}$ |
| Degree $d$: | $8$ |
| Ramification index $e$: | $8$ |
| Residue field degree $f$: | $1$ |
| Discriminant exponent $c$: | $16$ |
| Discriminant root field: | $\Q_{2}(\sqrt{5})$ |
| Root number: | $1$ |
| $\Aut(K/\Q_{2})$: | $C_4$ |
| This field is not Galois over $\Q_{2}.$ | |
| Visible Artin slopes: | $[2, 2, \frac{5}{2}]$ |
| Visible Swan slopes: | $[1,1,\frac{3}{2}]$ |
| Means: | $\langle\frac{1}{2}, \frac{3}{4}, \frac{9}{8}\rangle$ |
| Rams: | $(1, 1, 3)$ |
| Jump set: | $[1, 3, 9, 17]$ |
| Roots of unity: | $4 = 2^{ 2 }$ |
Intermediate fields
| $\Q_{2}(\sqrt{-1})$, 2.1.4.6a1.1 |
Fields in the database are given up to isomorphism. Isomorphic intermediate fields are shown with their multiplicities.
Canonical tower
| Unramified subfield: | $\Q_{2}$ |
| Relative Eisenstein polynomial: |
\( x^{8} + 2 x^{6} + 4 x + 2 \)
|
Ramification polygon
| Residual polynomials: | $z^6 + 1$,$z + 1$ |
| Associated inertia: | $2$,$1$ |
| Indices of inseparability: | $[9, 6, 6, 0]$ |
Invariants of the Galois closure
| Galois degree: | $32$ |
| Galois group: | $C_4\wr C_2$ (as 8T17) |
| Inertia group: | $Q_8$ (as 8T5) |
| Wild inertia group: | $Q_8$ |
| Galois unramified degree: | $4$ |
| Galois tame degree: | $1$ |
| Galois Artin slopes: | $[2, 2, \frac{5}{2}]$ |
| Galois Swan slopes: | $[1,1,\frac{3}{2}]$ |
| Galois mean slope: | $2.0$ |
| Galois splitting model: | $x^{8} - 2 x^{4} + 5$ |