Defining polynomial
\(x^{4} - 20\) ![]() |
Invariants
Base field: | $\Q_{2}$ |
Degree $d$: | $4$ |
Ramification exponent $e$: | $2$ |
Residue field degree $f$: | $2$ |
Discriminant exponent $c$: | $6$ |
Discriminant root field: | $\Q_{2}(\sqrt{-5})$ |
Root number: | $-i$ |
$|\Aut(K/\Q_{ 2 })|$: | $2$ |
This field is not Galois over $\Q_{2}.$ |
Intermediate fields
$\Q_{2}(\sqrt{5})$ |
Fields in the database are given up to isomorphism. Isomorphic intermediate fields are shown with their multiplicities.
Unramified/totally ramified tower
Unramified subfield: | $\Q_{2}(\sqrt{5})$ $\cong \Q_{2}(t)$ where $t$ is a root of \( x^{2} - x + 1 \) ![]() |
Relative Eisenstein polynomial: | \( x^{2} - 4 t - 6 \)$\ \in\Q_{2}(t)[x]$ ![]() |
Invariants of the Galois closure
Galois group: | $D_4$ (as 4T3) |
Inertia group: | Intransitive group isomorphic to $C_2^2$ |
Unramified degree: | $2$ |
Tame degree: | $1$ |
Wild slopes: | [2, 3] |
Galois mean slope: | $2$ |
Galois splitting model: | $x^{4} - 20$ |