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Defining polynomial

Copy content comment:Define the p-adic field
 
Copy content sage:Prec = 100 # Default precision of 100 Q5 = Qp(5, Prec); x = polygen(QQ) L.<t> = Q5.extension(x^2 + 4*x + 2) K.<a> = L.extension(x^10 + 5*x + 5)
 
Copy content magma:Prec := 100; // Default precision of 100 Q5 := pAdicField(5, Prec); K := LocalField(Q5, Polynomial(Q5, [1039, 20500, 189445, 1075200, 4189440, 11882496, 25390080, 41748480, 53527680, 53941760, 42904960, 26970880, 13381920, 5218560, 1586880, 371328, 65460, 8400, 740, 40, 1]));
 

$( x^{2} + 4 x + 2 )^{10} + 5 ( x^{2} + 4 x + 2 ) + 5$ Copy content Toggle raw display

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

Invariants

Base field: $\Q_{5}$
Copy content comment:Base field Qp
 
Copy content sage:K.base()
 
Copy content magma:Q5;
 
Degree $d$: $20$
Copy content comment:Degree over Qp
 
Copy content sage:K.absolute_degree()
 
Copy content magma:Degree(K);
 
Ramification index $e$:$10$
Copy content comment:Ramification index
 
Copy content sage:K.absolute_e()
 
Copy content magma:RamificationIndex(K);
 
Residue field degree $f$:$2$
Copy content comment:Residue field degree (Inertia degree)
 
Copy content sage:K.absolute_f()
 
Copy content magma:InertiaDegree(K);
 
Discriminant exponent $c$:$20$
Copy content comment:Discriminant exponent
 
Copy content magma:Valuation(Discriminant(K));
 
Discriminant root field:$\Q_{5}$
Root number: $1$
$\Aut(K/\Q_{5})$: $C_2$
This field is not Galois over $\Q_{5}.$
Visible Artin slopes:$[\frac{9}{8}]$
Visible Swan slopes:$[\frac{1}{8}]$
Means:$\langle\frac{1}{10}\rangle$
Rams:$(\frac{1}{4})$
Jump set:undefined
Roots of unity:$24 = (5^{ 2 } - 1)$
Copy content comment:Roots of unity
 
Copy content sage:len(K.roots_of_unity())
 

Intermediate fields

$\Q_{5}(\sqrt{2})$, $\Q_{5}(\sqrt{5})$, $\Q_{5}(\sqrt{5\cdot 2})$, 5.2.2.2a1.2, 5.1.10.10a1.1

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

Canonical tower

Unramified subfield:$\Q_{5}(\sqrt{2})$ $\cong \Q_{5}(t)$ where $t$ is a root of \( x^{2} + 4 x + 2 \) Copy content Toggle raw display
Copy content comment:Maximal unramified subextension
 
Copy content sage:K.maximal_unramified_subextension()
 
Relative Eisenstein polynomial: \( x^{10} + 5 x + 5 \) $\ \in\Q_{5}(t)[x]$ Copy content Toggle raw display

Ramification polygon

Residual polynomials:$z^5 + 2$,$2 z + 1$
Associated inertia:$1$,$1$
Indices of inseparability:$[1, 0]$

Invariants of the Galois closure

Galois degree: $400$
Galois group: $C_5^2:\OD_{16}$ (as 20T115)
Inertia group: Intransitive group isomorphic to $C_5^2:C_8$
Wild inertia group: $C_5^2$
Galois unramified degree: $2$
Galois tame degree: $8$
Galois Artin slopes: not computed
Galois Swan slopes: not computed
Galois mean slope: not computed
Galois splitting model:$x^{20} - 10 x^{18} + 65 x^{16} - 280 x^{14} + 910 x^{12} - 2174 x^{10} + 3920 x^{8} - 4940 x^{6} + 3865 x^{4} - 1380 x^{2} + 144$