Module

LocalHilbertExponentCompatibility.lean

Nyll.ClassFieldTheory.LocalClassFieldTheory.Kummer.LocalHilbertExponentCompatibility
1 declaration indexed from sourceView source ↗

Compatibility of local Hilbert symbols at divisible exponents

The source Hilbert symbol uses its first argument as the local Artin input and its second as the Kummer radical. Artin restriction along the actual simple Kummer tower makes its values compatible as the exponent varies.

Declarations

LocalClassFieldTheory.Kummer.localHilbertSymbol_exponentCompatibility

If m ∣ n, the exponent-m Hilbert value is the (n/m)-th power of the exponent-n value, compared as units of the base field.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
namespace LocalClassFieldTheory.Kummer
open RamificationTheory
theorem localHilbertSymbol_exponentCompatibility
    (K : Type) [Field K] [ValuativeRel K] [TopologicalSpace K]
    [IsNonarchimedeanLocalField K]
    (m n : ℕ+) (hmK : ((m : ℕ) : K) ≠ 0)
    (hnK : ((n : ℕ) : K) ≠ 0)
    (hmuM : (primitiveRoots (m : ℕ) K).Nonempty)
    (hmuN : (primitiveRoots (n : ℕ) K).Nonempty)
    (hmn : (m : ℕ) ∣ (n : ℕ)) (a b : Kˣ) :
    (localHilbertSymbol K m hmK hmuM a b).1 =
      (localHilbertSymbol K n hnK hmuN a b).1 ^ ((n : ℕ) / (m : ℕ))