Properties

Label 5.4.2.4a1.2
Base \(\Q_{5}\)
Degree \(8\)
e \(2\)
f \(4\)
c \(4\)
Galois group $C_4\times C_2$ (as 8T2)

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Defining polynomial

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

Invariants

Base field: $\Q_{5}$
Degree $d$: $8$
Ramification index $e$: $2$
Residue field degree $f$: $4$
Discriminant exponent $c$: $4$
Discriminant root field: $\Q_{5}$
Root number: $-1$
$\Aut(K/\Q_{5})$ $=$$\Gal(K/\Q_{5})$: $C_2\times C_4$
This field is Galois and abelian over $\Q_{5}.$
Visible Artin slopes:$[\ ]$
Visible Swan slopes:$[\ ]$
Means:$\langle\ \rangle$
Rams:$(\ )$
Jump set:undefined
Roots of unity:$624 = (5^{ 4 } - 1)$

Intermediate fields

$\Q_{5}(\sqrt{2})$, $\Q_{5}(\sqrt{5})$, $\Q_{5}(\sqrt{5\cdot 2})$, 5.4.1.0a1.1, 5.2.2.2a1.2, 5.2.2.2a1.1

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

Canonical tower

Unramified subfield:5.4.1.0a1.1 $\cong \Q_{5}(t)$ where $t$ is a root of \( x^{4} + 4 x^{2} + 4 x + 2 \) Copy content Toggle raw display
Relative Eisenstein polynomial: \( x^{2} + 5 \) $\ \in\Q_{5}(t)[x]$ Copy content Toggle raw display

Ramification polygon

Residual polynomials:$z + 2$
Associated inertia:$1$
Indices of inseparability:$[0]$

Invariants of the Galois closure

Galois degree: $8$
Galois group: $C_2\times C_4$ (as 8T2)
Inertia group: Intransitive group isomorphic to $C_2$
Wild inertia group: $C_1$
Galois unramified degree: $4$
Galois tame degree: $2$
Galois Artin slopes: $[\ ]$
Galois Swan slopes: $[\ ]$
Galois mean slope: $0.5$
Galois splitting model:$x^{8} + 12 x^{6} + 30 x^{4} + 24 x^{2} + 4$