Properties

Label 2.2.8.54a1.1232
Base \(\Q_{2}\)
Degree \(16\)
e \(8\)
f \(2\)
c \(54\)
Galois group $D_8:C_4$ (as 16T114)

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Defining polynomial

$( x^{2} + x + 1 )^{8} + 4 ( x^{2} + x + 1 )^{6} + \left(8 x + 2\right) ( x^{2} + x + 1 )^{4} + 16 x ( x^{2} + x + 1 )^{3} + 2$ Copy content Toggle raw display

Invariants

Base field: $\Q_{2}$
Degree $d$: $16$
Ramification index $e$: $8$
Residue field degree $f$: $2$
Discriminant exponent $c$: $54$
Discriminant root field: $\Q_{2}$
Root number: $1$
$\Aut(K/\Q_{2})$: $C_8$
This field is not Galois over $\Q_{2}.$
Visible Artin slopes:$[2, \frac{7}{2}, \frac{9}{2}]$
Visible Swan slopes:$[1,\frac{5}{2},\frac{7}{2}]$
Means:$\langle\frac{1}{2}, \frac{3}{2}, \frac{5}{2}\rangle$
Rams:$(1, 4, 8)$
Jump set:$[1, 5, 13, 21]$
Roots of unity:$12 = (2^{ 2 } - 1) \cdot 2^{ 2 }$

Intermediate fields

$\Q_{2}(\sqrt{-5})$, $\Q_{2}(\sqrt{5})$, $\Q_{2}(\sqrt{-1})$, 2.2.2.4a1.1, 2.2.4.18a1.10

Fields in the database are given up to isomorphism. Isomorphic intermediate fields are shown with their multiplicities.

Canonical tower

Unramified subfield:$\Q_{2}(\sqrt{5})$ $\cong \Q_{2}(t)$ where $t$ is a root of \( x^{2} + x + 1 \) Copy content Toggle raw display
Relative Eisenstein polynomial: \( x^{8} + 4 x^{6} + 8 x^{5} + \left(8 t + 2\right) x^{4} + \left(16 t + 16\right) x^{3} + 16 x + 2 \) $\ \in\Q_{2}(t)[x]$ 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:$[20, 12, 4, 0]$

Invariants of the Galois closure

Galois degree: $64$
Galois group: $D_8:C_4$ (as 16T114)
Inertia group: Intransitive group isomorphic to $C_4\wr C_2$
Wild inertia group: $C_4\wr C_2$
Galois unramified degree: $2$
Galois tame degree: $1$
Galois Artin slopes: $[2, 3, \frac{7}{2}, 4, \frac{9}{2}]$
Galois Swan slopes: $[1,2,\frac{5}{2},3,\frac{7}{2}]$
Galois mean slope: $3.9375$
Galois splitting model:$x^{16} + 12 x^{12} + 360 x^{8} + 864 x^{4} + 576$