Properties

Label 2.1.8.20c1.4
Base \(\Q_{2}\)
Degree \(8\)
e \(8\)
f \(1\)
c \(20\)
Galois group $S_4\times C_2$ (as 8T24)

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Defining polynomial

\(x^{8} + 4 x^{7} + 4 x^{5} + 4 x^{2} + 10\) Copy content Toggle raw display

Invariants

Base field: $\Q_{2}$
Degree $d$: $8$
Ramification index $e$: $8$
Residue field degree $f$: $1$
Discriminant exponent $c$: $20$
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:$2$

Intermediate fields

$\Q_{2}(\sqrt{2\cdot 5})$, 2.1.4.8a1.2

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: \( x^{8} + 4 x^{7} + 4 x^{5} + 4 x^{2} + 10 \) Copy content Toggle raw display

Ramification polygon

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

Invariants of the Galois closure

Galois degree: $48$
Galois group: $C_2\times S_4$ (as 8T24)
Inertia group: $C_2\times A_4$ (as 8T13)
Wild inertia group: $C_2^3$
Galois unramified degree: $2$
Galois tame degree: $3$
Galois Artin slopes: $[\frac{8}{3}, \frac{8}{3}, 3]$
Galois Swan slopes: $[\frac{5}{3},\frac{5}{3},2]$
Galois mean slope: $2.5833333333333335$
Galois splitting model:$x^{8} - 4 x^{7} + 4 x^{6} - 12 x^{5} + 24 x^{4} + 36 x^{2} + 22$