Properties

Label 2.2.8.40c2.19
Base \(\Q_{2}\)
Degree \(16\)
e \(8\)
f \(2\)
c \(40\)
Galois group $C_2^4.S_4$ (as 16T750)

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Defining polynomial

$( x^{2} + x + 1 )^{8} + 4 x ( x^{2} + x + 1 )^{7} + 4 x ( x^{2} + x + 1 )^{5} + 4 ( x^{2} + x + 1 )^{4} + 4 ( x^{2} + x + 1 )^{2} + 2$ Copy content Toggle raw display

Invariants

Base field: $\Q_{2}$
Degree $d$: $16$
Ramification index $e$: $8$
Residue field degree $f$: $2$
Discriminant exponent $c$: $40$
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:$[\frac{8}{3}, \frac{8}{3}, 3]$
Visible Swan slopes:$[\frac{5}{3},\frac{5}{3},2]$
Means:$\langle\frac{5}{6}, \frac{5}{4}, \frac{13}{8}\rangle$
Rams:$(\frac{5}{3}, \frac{5}{3}, 3)$
Jump set:$[1, 3, 7, 15]$
Roots of unity:$6 = (2^{ 2 } - 1) \cdot 2$

Intermediate fields

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

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: \( x^{8} + 4 x^{7} + 4 t x^{5} + 4 x^{4} + 4 x^{2} + 10 \) $\ \in\Q_{2}(t)[x]$ Copy content Toggle raw display

Ramification polygon

Residual polynomials:$z^2 + 1$,$z + t$
Associated inertia:$1$,$1$
Indices of inseparability:$[13, 10, 8, 0]$

Invariants of the Galois closure

Galois degree: $384$
Galois group: $C_2^4.S_4$ (as 16T750)
Inertia group: Intransitive group isomorphic to $C_2^4:A_4$
Wild inertia group: $D_4:C_2^3$
Galois unramified degree: $2$
Galois tame degree: $3$
Galois Artin slopes: $[\frac{4}{3}, \frac{4}{3}, \frac{8}{3}, \frac{8}{3}, 3, 3]$
Galois Swan slopes: $[\frac{1}{3},\frac{1}{3},\frac{5}{3},\frac{5}{3},2,2]$
Galois mean slope: $2.8229166666666665$
Galois splitting model: $x^{16} - 8 x^{15} - 16 x^{14} + 204 x^{13} - 1504 x^{12} - 304 x^{11} + 21400 x^{10} - 66840 x^{9} - 8978 x^{8} + 1031640 x^{7} - 161360 x^{6} - 4471448 x^{5} + 19415936 x^{4} + 4235472 x^{3} - 146951704 x^{2} + 156967424 x - 23726804$ Copy content Toggle raw display