Properties

Label 2.1.8.28b1.14
Base \(\Q_{2}\)
Degree \(8\)
e \(8\)
f \(1\)
c \(28\)
Galois group $C_2^3 : C_4 $ (as 8T19)

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Defining polynomial

\(x^{8} + 8 x^{6} + 8 x^{5} + 8 x^{2} + 18\) Copy content Toggle raw display

Invariants

Base field: $\Q_{2}$
Degree $d$: $8$
Ramification index $e$: $8$
Residue field degree $f$: $1$
Discriminant exponent $c$: $28$
Discriminant root field: $\Q_{2}$
Root number: $1$
$\Aut(K/\Q_{2})$: $C_2$
This field is not Galois over $\Q_{2}.$
Visible Artin slopes:$[3, 4, \frac{17}{4}]$
Visible Swan slopes:$[2,3,\frac{13}{4}]$
Means:$\langle1, 2, \frac{21}{8}\rangle$
Rams:$(2, 4, 5)$
Jump set:$[1, 3, 7, 15]$
Roots of unity:$2$

Intermediate fields

$\Q_{2}(\sqrt{-2})$, 2.1.4.11a1.1

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: \( x^{8} + 8 x^{6} + 8 x^{5} + 8 x^{2} + 18 \) Copy content Toggle raw display

Ramification polygon

Residual polynomials:$z^4 + 1$,$z^2 + 1$,$z + 1$
Associated inertia:$1$,$1$,$1$
Indices of inseparability:$[21, 16, 8, 0]$

Invariants of the Galois closure

Galois degree: $32$
Galois group: $C_2^3:C_4$ (as 8T19)
Inertia group: $C_2^3:C_4$ (as 8T19)
Wild inertia group: $C_2^3:C_4$
Galois unramified degree: $1$
Galois tame degree: $1$
Galois Artin slopes: $[2, 3, \frac{7}{2}, 4, \frac{17}{4}]$
Galois Swan slopes: $[1,2,\frac{5}{2},3,\frac{13}{4}]$
Galois mean slope: $3.8125$
Galois splitting model:$x^{8} - 4 x^{6} + 10 x^{4} + 4 x^{2} + 1$