Module

RadicalValueGroup.lean

Nyll.SchemeTheory.AbhyankarLemma.TameRamification.Book.RadicalValueGroup
1 declaration indexed from sourceView source ↗

Value groups generated by a finite tame radical family

This file lifts the one-radical value-group calculation to the finite radical presentation supplied by Proposition 7.7.

Imports29
Imported by2

Declarations

TameAbhyankar.bookExponentialValueSubgroup_eq_sup_iSup_zmultiples_of_radical_family

A finite family of prime-to-the-residue-characteristic radicals which generates the field also generates its value group.

Source context 5 commands

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

noncomputable section
universe u
namespace TameAbhyankar
open AlgebraicNumberTheory.Valuations
open scoped IntermediateField
theorem bookExponentialValueSubgroup_eq_sup_iSup_zmultiples_of_radical_family
    {K L : Type u} [Field K] [Field L] [Algebra K L]
    [FiniteDimensional K L]
    (v : LubinTate.Valuations.ExponentialValuation K)
    (w : LubinTate.Valuations.ExponentialValuation L)
    (hExt : ∀ a : K, w (algebraMap K L a) = v a)
    (hhens : ValuationTheory.DiscreteValuationField.HenselianValuationByFactorization
      (LubinTate.Valuations.exponentialValuationSubringAsValuationSubring v).valuation)
    (hp : PositiveResidueCharacteristic v)
    (hres : Function.Surjective (tameResidueFieldMap v w hExt))
    (r : ℕ) (m : Fin r → ℕ) (a : Fin r → K) (alpha : Fin r → L)
    (hmpos : ∀ i, 0 < m i)
    (hmcop : ∀ i, Nat.Coprime (m i) (residueCharacteristic v))
    (hpow : ∀ i, alpha i ^ m i = algebraMap K L (a i))
    (hgen : IntermediateField.adjoin K (Set.range alpha) = ⊤) :
    exponentialValueSubgroup w =
      exponentialValueSubgroup v ⊔
        ⨆ i, AddSubgroup.zmultiples (w (alpha i)).untop₀