$p$-adic field 2.2.8.42a1.25

• Label: 2.2.8.42a1.25
• Base: \(\Q_{2}\)
• Degree: \(16\)
• e: \(8\)
• f: \(2\)
• c: \(42\)
• Galois group: $C_2^6.D_4$ (as 16T834)

Defining polynomial

$( x^{2} + x + 1 )^{8} + 4 x ( x^{2} + x + 1 )^{7} + 2 ( x^{2} + x + 1 )^{6} + 8 ( x^{2} + x + 1 )^{5} + 2$

Invariants

Base field:	$\Q_{2}$
Degree $d$:	$16$
Ramification index $e$:	$8$
Residue field degree $f$:	$2$
Discriminant exponent $c$:	$42$
Discriminant root field:	$\Q_{2}(\sqrt{5})$
Root number:	$1$
$\Aut(K/\Q_{2})$:	$C_2$
This field is not Galois over $\Q_{2}.$
Visible Artin slopes:	$[2, 2, \frac{15}{4}]$
Visible Swan slopes:	$[1,1,\frac{11}{4}]$
Means:	$\langle\frac{1}{2}, \frac{3}{4}, \frac{7}{4}\rangle$
Rams:	$(1, 1, 8)$
Jump set:	$[1, 3, 11, 19]$
Roots of unity:	$12 = (2^{ 2 } - 1) \cdot 2^{ 2 }$

Intermediate fields

$\Q_{2}(\sqrt{5})$, $\Q_{2}(\sqrt{-1})$, $\Q_{2}(\sqrt{-5})$, 2.2.2.4a1.1, 2.2.2.4a2.2 x2, 2.1.4.6a1.1 x2, 2.2.4.12a1.1

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 \( x^{2} + x + 1 \)
Relative Eisenstein polynomial:	\( x^{8} + \left(4 t + 4\right) x^{7} + \left(8 t + 2\right) x^{6} + 8 t x^{5} + \left(8 t + 8\right) x^{3} + 2 \) $\ \in\Q_{2}(t)[x]$

Ramification polygon

Residual polynomials:	$z^6 + 1$,$z + 1$
Associated inertia:	$1$,$1$
Indices of inseparability:	$[14, 6, 6, 0]$

Invariants of the Galois closure

Galois degree:	$512$
Galois group:	$C_2^6.D_4$ (as 16T834)
Inertia group:	not computed
Wild inertia group:	not computed
Galois unramified degree:	$4$
Galois tame degree:	$1$
Galois Artin slopes:	$[2, 2, \frac{5}{2}, 3, \frac{7}{2}, \frac{7}{2}, \frac{15}{4}]$
Galois Swan slopes:	$[1,1,\frac{3}{2},2,\frac{5}{2},\frac{5}{2},\frac{11}{4}]$
Galois mean slope:	$3.5$
Galois splitting model:	not computed