Properties

Label 2.2.8.48c3.443
Base \(\Q_{2}\)
Degree \(16\)
e \(8\)
f \(2\)
c \(48\)
Galois group $C_4^2.(C_2\times C_4)$ (as 16T362)

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Defining polynomial

$( x^{2} + x + 1 )^{8} + 12 ( x^{2} + x + 1 )^{7} + 4 x ( x^{2} + x + 1 )^{6} + 2 ( x^{2} + x + 1 )^{4} + \left(8 x + 4\right) ( x^{2} + x + 1 )^{3} + \left(4 x + 4\right) ( x^{2} + x + 1 )^{2} + \left(8 x + 4\right) ( x^{2} + x + 1 ) + 4 x + 2$ Copy content Toggle raw display

Invariants

Base field: $\Q_{2}$
Degree $d$: $16$
Ramification index $e$: $8$
Residue field degree $f$: $2$
Discriminant exponent $c$: $48$
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:$[2, 3, 4]$
Visible Swan slopes:$[1,2,3]$
Means:$\langle\frac{1}{2}, \frac{5}{4}, \frac{17}{8}\rangle$
Rams:$(1, 3, 7)$
Jump set:$[1, 2, 4, 16]$
Roots of unity:$6 = (2^{ 2 } - 1) \cdot 2$

Intermediate fields

$\Q_{2}(\sqrt{5})$, 2.2.2.4a1.2, 2.2.4.16b2.9

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: \( x^{8} + 8 t x^{7} + \left(4 t + 4\right) x^{6} + 8 t x^{5} + 2 x^{4} + 8 t x^{3} + \left(4 t + 4\right) x^{2} + 8 x + 4 t + 2 \) $\ \in\Q_{2}(t)[x]$ Copy content Toggle raw display

Ramification polygon

Residual polynomials:$z^4 + 1$,$z^2 + t$,$t z + 1$
Associated inertia:$1$,$1$,$1$
Indices of inseparability:$[17, 10, 4, 0]$

Invariants of the Galois closure

Galois degree: $128$
Galois group: $C_4^2.(C_2\times C_4)$ (as 16T362)
Inertia group: Intransitive group isomorphic to $C_8:C_4$
Wild inertia group: $C_8:C_4$
Galois unramified degree: $4$
Galois tame degree: $1$
Galois Artin slopes: $[2, 3, 3, 4, 4]$
Galois Swan slopes: $[1,2,2,3,3]$
Galois mean slope: $3.625$
Galois splitting model: $x^{16} + 10 x^{12} + 10 x^{8} - 50 x^{4} + 25$ Copy content Toggle raw display