Properties

Label 2.2.8.56a1.304
Base \(\Q_{2}\)
Degree \(16\)
e \(8\)
f \(2\)
c \(56\)
Galois group $C_4^3:(C_2\times C_4)$ (as 16T864)

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Defining polynomial

$( x^{2} + x + 1 )^{8} + \left(8 x + 8\right) ( x^{2} + x + 1 )^{7} + 4 ( x^{2} + x + 1 )^{6} + 8 ( x^{2} + x + 1 )^{5} + \left(16 x + 16\right) ( x^{2} + x + 1 )^{3} + 8 ( x^{2} + x + 1 )^{2} + 8 ( x^{2} + x + 1 ) + 8 x + 2$ Copy content Toggle raw display

Invariants

Base field: $\Q_{2}$
Degree $d$: $16$
Ramification index $e$: $8$
Residue field degree $f$: $2$
Discriminant exponent $c$: $56$
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:$[3, \frac{7}{2}, \frac{9}{2}]$
Visible Swan slopes:$[2,\frac{5}{2},\frac{7}{2}]$
Means:$\langle1, \frac{7}{4}, \frac{21}{8}\rangle$
Rams:$(2, 3, 7)$
Jump set:$[1, 3, 7, 15]$
Roots of unity:$6 = (2^{ 2 } - 1) \cdot 2$

Intermediate fields

$\Q_{2}(\sqrt{5})$, 2.2.2.6a1.6, 2.2.4.20a1.5

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: \( x^{8} + 8 t x^{7} + 4 x^{6} + 8 x^{5} + \left(16 t + 16\right) x^{3} + 8 x^{2} + 8 t + 2 \) $\ \in\Q_{2}(t)[x]$ 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:$[21, 14, 8, 0]$

Invariants of the Galois closure

Galois degree: $512$
Galois group: $C_4^3:(C_2\times C_4)$ (as 16T864)
Inertia group: not computed
Wild inertia group: not computed
Galois unramified degree: $4$
Galois tame degree: $1$
Galois Artin slopes: $[2, 2, 3, 3, \frac{7}{2}, 4, \frac{9}{2}]$
Galois Swan slopes: $[1,1,2,2,\frac{5}{2},3,\frac{7}{2}]$
Galois mean slope: $4.015625$
Galois splitting model:not computed