Properties

Label 2.5.4.55a1.6850
Base \(\Q_{2}\)
Degree \(20\)
e \(4\)
f \(5\)
c \(55\)
Galois group $C_{20}$ (as 20T1)

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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 + 8*x^3 + 4*x^2 + 26)
 
Copy content magma:Prec := 100; // Default precision of 100 Q2 := pAdicField(2, Prec); K := LocalField(Q2, Polynomial(Q2, [39, 0, 36, 0, 34, 36, 12, 68, 1, 36, 34, 4, 36, 0, 6, 12, 0, 4, 0, 0, 1]));
 

$( x^{5} + x^{2} + 1 )^{4} + 8 ( x^{5} + x^{2} + 1 )^{3} + 4 ( x^{5} + x^{2} + 1 )^{2} + 26$ 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 $c$:$55$
Copy content comment:Discriminant exponent
 
Copy content magma:Valuation(Discriminant(K));
 
Discriminant root field:$\Q_{2}(\sqrt{2\cdot 5})$
Root number: $1$
$\Aut(K/\Q_{2})$ $=$ $\Gal(K/\Q_{2})$: $C_{20}$
This field is Galois and abelian over $\Q_{2}.$
Visible Artin slopes:$[3, 4]$
Visible Swan slopes:$[2,3]$
Means:$\langle1, 2\rangle$
Rams:$(2, 4)$
Jump set:$[1, 3, 7]$
Roots of unity:$62 = (2^{ 5 } - 1) \cdot 2$
Copy content comment:Roots of unity
 
Copy content sage:len(K.roots_of_unity())
 

Intermediate fields

$\Q_{2}(\sqrt{2\cdot 5})$, 2.1.4.11a1.18, 2.5.1.0a1.1, 2.5.2.15a1.10

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: \( x^{4} + 8 x^{3} + 4 x^{2} + 26 \) $\ \in\Q_{2}(t)[x]$ Copy content Toggle raw display

Ramification polygon

Residual polynomials:$z^2 + (t^4 + t^3 + t + 1)$,$(t^4 + t^3 + t + 1) z + t$
Associated inertia:$1$,$1$
Indices of inseparability:$[8, 4, 0]$

Invariants of the Galois closure

Galois degree: $20$
Galois group: $C_{20}$ (as 20T1)
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