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Defining polynomial

Copy content comment:Define the p-adic field
 
Copy content sage:Prec = 100 # Default precision of 100 Q2 = Qp(2, Prec); x = polygen(QQ) K.<a> = Q2.extension(x^8 + 2*x^7 + 6)
 
Copy content magma:Prec := 100; // Default precision of 100 Q2 := pAdicField(2, Prec); K := LocalField(Q2, Polynomial(Q2, [6, 0, 0, 0, 0, 0, 0, 2, 1]));
 

\(x^{8} + 2 x^{7} + 6\) Copy content Toggle raw display

Copy content comment:Defining polynomial
 
Copy content sage:K.defining_polynomial()
 
Copy content magma:DefiningPolynomial(K);
 

Invariants

Base field: $\Q_{2}$
Copy content comment:Base field Qp
 
Copy content sage:K.base()
 
Copy content magma:Q2;
 
Degree $d$: $8$
Copy content comment:Degree over Qp
 
Copy content sage:K.absolute_degree()
 
Copy content magma:Degree(K);
 
Ramification index $e$:$8$
Copy content comment:Ramification index
 
Copy content sage:K.absolute_e()
 
Copy content magma:RamificationIndex(K);
 
Residue field degree $f$:$1$
Copy content comment:Residue field degree (Inertia degree)
 
Copy content sage:K.absolute_f()
 
Copy content magma:InertiaDegree(K);
 
Discriminant exponent $c$:$14$
Copy content comment:Discriminant exponent
 
Copy content magma:Valuation(Discriminant(K));
 
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:$[2, 2, 2]$
Visible Swan slopes:$[1,1,1]$
Means:$\langle\frac{1}{2}, \frac{3}{4}, \frac{7}{8}\rangle$
Rams:$(1, 1, 1)$
Jump set:$[1, 3, 7, 16]$
Roots of unity:$2$
Copy content comment:Roots of unity
 
Copy content sage:len(K.roots_of_unity())
 

Intermediate fields

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

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

Canonical tower

Unramified subfield:$\Q_{2}$
Copy content comment:Maximal unramified subextension
 
Copy content sage:K.maximal_unramified_subextension()
 
Relative Eisenstein polynomial: \( x^{8} + 2 x^{7} + 6 \) Copy content Toggle raw display

Ramification polygon

Residual polynomials:$z^7 + 1$
Associated inertia:$3$
Indices of inseparability:$[7, 7, 7, 0]$

Invariants of the Galois closure

Galois degree: $24$
Galois group: $C_2\times A_4$ (as 8T13)
Inertia group: $C_2^3$ (as 8T3)
Wild inertia group: $C_2^3$
Galois unramified degree: $3$
Galois tame degree: $1$
Galois Artin slopes: $[2, 2, 2]$
Galois Swan slopes: $[1,1,1]$
Galois mean slope: $1.75$
Galois splitting model:$x^{8} - 2 x^{7} - 2 x^{6} + 2 x^{5} + 8 x^{4} + 2 x^{3} - 2 x^{2} - 2 x + 1$