Module

LocalTameCharacterConjugateValue.lean

Nyll.ValuedFieldTheory.Ramification.HilbertRamification.LocalTameCharacterConjugateValue
1 declaration indexed from sourceView source ↗

Conjugation values of the local tame character

Computes powers of the local tame character on conjugate inertia elements using the root-group map induced by the residue-field action.

Declarations

RamificationTheory.HilbertRamification.DiscreteValuationRing.localTameCharacterGroupMap_pow_conj_value

The proved same-character equation on the literal conjugate, using the existing native map of roots induced by the standard residue coefficient map.

Source context 5 commands

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

noncomputable section
namespace RamificationTheory.HilbertRamification.DiscreteValuationRing
open IsLocalRing
universe u
attribute [local instance] maximalIdeal_inertia_normal
theorem localTameCharacterGroupMap_pow_conj_value
    (R G : Type u) [CommRing R] [IsDomain R] [IsDiscreteValuationRing R]
    [Group G] [Finite G] [MulSemiringAction G R]
    (m : ℕ) (g : G) (σ : (maximalIdeal R).inertia G) :
    ((localTameCharacterGroupMap R G).toFun
      ⟨g * σ.val * g⁻¹, (maximalIdeal_inertia_normal R G).conj_mem σ.val σ.property g⟩) ^ m =
      (rootsGroupMap (MulSemiringAction.toRingHom G (ResidueField R) g)
        (tameOrder R G)).hom'.toFun (((localTameCharacterGroupMap R G).toFun σ) ^ m)