Properties

Label 2.1.8.18b1.12
Base \(\Q_{2}\)
Degree \(8\)
e \(8\)
f \(1\)
c \(18\)
Galois group $QD_{16}$ (as 8T8)

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Defining polynomial

\(x^{8} + 4 x^{7} + 2 x^{6} + 4 x^{5} + 4 x^{3} + 6\) Copy content Toggle raw display

Invariants

Base field: $\Q_{2}$
Degree $d$: $8$
Ramification index $e$: $8$
Residue field degree $f$: $1$
Discriminant exponent $c$: $18$
Discriminant root field: $\Q_{2}(\sqrt{5})$
Root number: $1$
$\Aut(K/\Q_{2})$: $C_2$
This field is not Galois over $\Q_{2}.$
Visible Artin slopes:$[2, 2, 3]$
Visible Swan slopes:$[1,1,2]$
Means:$\langle\frac{1}{2}, \frac{3}{4}, \frac{11}{8}\rangle$
Rams:$(1, 1, 5)$
Jump set:$[1, 3, 6, 16]$
Roots of unity:$2$

Intermediate fields

$\Q_{2}(\sqrt{-5})$, 2.1.4.6a1.2

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: \( x^{8} + 4 x^{7} + 2 x^{6} + 4 x^{5} + 4 x^{3} + 6 \) Copy content Toggle raw display

Ramification polygon

Residual polynomials:$z^6 + 1$,$z + 1$
Associated inertia:$2$,$1$
Indices of inseparability:$[11, 6, 6, 0]$

Invariants of the Galois closure

Galois degree: $16$
Galois group: $\SD_{16}$ (as 8T8)
Inertia group: $Q_8$ (as 8T5)
Wild inertia group: $Q_8$
Galois unramified degree: $2$
Galois tame degree: $1$
Galois Artin slopes: $[2, 2, 3]$
Galois Swan slopes: $[1,1,2]$
Galois mean slope: $2.25$
Galois splitting model:$x^{8} - 6 x^{4} - 3$