Properties

Label 2.1.8.26b1.8
Base \(\Q_{2}\)
Degree \(8\)
e \(8\)
f \(1\)
c \(26\)
Galois group $C_2^3 : C_4 $ (as 8T19)

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Defining polynomial

\(x^{8} + 8 x^{7} + 8 x^{5} + 2 x^{4} + 8 x^{3} + 16 x^{2} + 2\) Copy content Toggle raw display

Invariants

Base field: $\Q_{2}$
Degree $d$: $8$
Ramification index $e$: $8$
Residue field degree $f$: $1$
Discriminant exponent $c$: $26$
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:$[2, \frac{7}{2}, \frac{17}{4}]$
Visible Swan slopes:$[1,\frac{5}{2},\frac{13}{4}]$
Means:$\langle\frac{1}{2}, \frac{3}{2}, \frac{19}{8}\rangle$
Rams:$(1, 4, 7)$
Jump set:$[1, 5, 13, 21]$
Roots of unity:$4 = 2^{ 2 }$

Intermediate fields

$\Q_{2}(\sqrt{-1})$, 2.1.4.9a1.3

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: \( x^{8} + 8 x^{7} + 8 x^{5} + 2 x^{4} + 8 x^{3} + 16 x^{2} + 2 \) 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:$[19, 12, 4, 0]$

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:$x^{8} - 12 x^{6} + 60 x^{4} - 120 x^{2} + 100$