Properties

Label 2.1.4.8b1.5
Base \(\Q_{2}\)
Degree \(4\)
e \(4\)
f \(1\)
c \(8\)
Galois group $C_2^2$ (as 4T2)

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Defining polynomial

\(x^{4} + 4 x^{3} + 2 x^{2} + 4 x + 6\) Copy content Toggle raw display

Invariants

Base field: $\Q_{2}$
Degree $d$: $4$
Ramification index $e$: $4$
Residue field degree $f$: $1$
Discriminant exponent $c$: $8$
Discriminant root field: $\Q_{2}$
Root number: $1$
$\Aut(K/\Q_{2})$ $=$$\Gal(K/\Q_{2})$: $C_2^2$
This field is Galois and abelian over $\Q_{2}.$
Visible Artin slopes:$[2, 3]$
Visible Swan slopes:$[1,2]$
Means:$\langle\frac{1}{2}, \frac{5}{4}\rangle$
Rams:$(1, 3)$
Jump set:$[1, 2, 8]$
Roots of unity:$2$

Intermediate fields

$\Q_{2}(\sqrt{-5})$, $\Q_{2}(\sqrt{-2})$, $\Q_{2}(\sqrt{2\cdot 5})$

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: \( x^{4} + 4 x^{3} + 2 x^{2} + 4 x + 6 \) Copy content Toggle raw display

Ramification polygon

Residual polynomials:$z^2 + 1$,$z + 1$
Associated inertia:$1$,$1$
Indices of inseparability:$[5, 2, 0]$

Invariants of the Galois closure

Galois degree: $4$
Galois group: $C_2^2$ (as 4T2)
Inertia group: $C_2^2$ (as 4T2)
Wild inertia group: $C_2^2$
Galois unramified degree: $1$
Galois tame degree: $1$
Galois Artin slopes: $[2, 3]$
Galois Swan slopes: $[1,2]$
Galois mean slope: $2.0$
Galois splitting model:$x^{4} + 4 x^{2} + 1$