Properties

Label 2.5.4.40b2.28
Base \(\Q_{2}\)
Degree \(20\)
e \(4\)
f \(5\)
c \(40\)
Galois group not computed

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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) L.<t> = Q2.extension(x^5 + x^2 + 1) K.<a> = L.extension(x^4 + 4*t*x^3 + 2*x^2 + 4*t^4*x + 2)
 
Copy content magma:Prec := 100; // Default precision of 100 Q2 := pAdicField(2, Prec); K := LocalField(Q2, Polynomial(Q2, [9, 8, 28, 20, 20, 44, 24, 56, 37, 28, 56, 16, 36, 24, 6, 20, 4, 4, 4, 0, 1]));
 

$( x^{5} + x^{2} + 1 )^{4} + \left(4 x^{3} + 4 x + 4\right) ( x^{5} + x^{2} + 1 )^{3} + 2 ( x^{5} + x^{2} + 1 )^{2} + 4 x ( x^{5} + x^{2} + 1 ) + 8 x^{2} + 2$ 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 $d$: $20$
Copy content comment:Degree over Qp
 
Copy content sage:K.absolute_degree()
 
Copy content magma:Degree(K);
 
Ramification index $e$:$4$
Copy content comment:Ramification index
 
Copy content sage:K.absolute_e()
 
Copy content magma:RamificationIndex(K);
 
Residue field degree $f$:$5$
Copy content comment:Residue field degree (Inertia degree)
 
Copy content sage:K.absolute_f()
 
Copy content magma:InertiaDegree(K);
 
Discriminant exponent $c$:$40$
Copy content comment:Discriminant exponent
 
Copy content magma:Valuation(Discriminant(K));
 
Discriminant root field:$\Q_{2}$
Root number: $1$
$\Aut(K/\Q_{2})$: $C_2$
Visible Artin slopes:$[2, 3]$
Visible Swan slopes:$[1,2]$
Means:$\langle\frac{1}{2}, \frac{5}{4}\rangle$
Rams:$(1, 3)$
Jump set:$[1, 5, 9]$
Roots of unity:$124 = (2^{ 5 } - 1) \cdot 2^{ 2 }$
Copy content comment:Roots of unity
 
Copy content sage:len(K.roots_of_unity())
 

Intermediate fields

$\Q_{2}(\sqrt{-1})$, 2.5.1.0a1.1, 2.5.2.10a1.1

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

Canonical tower

Unramified subfield:2.5.1.0a1.1 $\cong \Q_{2}(t)$ where $t$ is a root of \( x^{5} + x^{2} + 1 \) Copy content Toggle raw display
Copy content comment:Maximal unramified subextension
 
Copy content sage:K.maximal_unramified_subextension()
 
Relative Eisenstein polynomial: \( x^{4} + 4 t x^{3} + 2 x^{2} + 4 t^{4} x + 2 \) $\ \in\Q_{2}(t)[x]$ Copy content Toggle raw display

Ramification polygon

Residual polynomials:$z^2 + (t^3 + t^2 + 1)$,$(t^3 + t^2 + 1) z + (t^4 + t^3)$
Associated inertia:$1$,$1$
Indices of inseparability:$[5, 2, 0]$

Invariants of the Galois closure

Galois degree: not computed
Galois group: not computed
Inertia group: not computed
Wild inertia group: not computed
Galois unramified degree: not computed
Galois tame degree: not computed
Galois Artin slopes: not computed
Galois Swan slopes: not computed
Galois mean slope: not computed
Galois splitting model:not computed