Module

LevelValuation.lean

Nyll.ClassFieldTheory.LubinTate.FiniteLevel.LevelValuation
2 declarations indexed from sourceView source ↗

Uniqueness of the valuation on standard Lubin--Tate levels

The standard level field is finite and Galois over the local base field. Consequently the complete discrete valuation selected from its integral closure is the unique extension of the base valuation. This is the bridge needed by the genuine lower- and upper-numbering ramification groups.

Declarations

LubinTate.standardLubinTateLevelCompleteDVF_hasUniqueValuationExtension

The chosen complete valuation on a standard Lubin--Tate level is the unique extension of the base valuation.

Source context 7 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open ValuationTheory.DiscreteValuationField.ValuedExtension
variable {K : Type u} [Field K]
open _root_.ValuationTheory.DiscreteValuationField.ValuedExtension (
  HasUniqueValuationExtension
) in
theorem standardLubinTateLevelCompleteDVF_hasUniqueValuationExtension
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    HasUniqueValuationExtension.{u, v, u, 0, 0}
      (base := F.toCompleteDVF)
      (target := standardLubinTateLevelCompleteDVF hπ n)
LubinTate.standardLubinTateLevelCompleteDVF_hasUniqueDVFValuationExtension

The same uniqueness statement after forgetting completeness, in the form used by the real ramification-group API.

Source context 6 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open ValuationTheory.DiscreteValuationField.ValuedExtension
variable {K : Type u} [Field K]
theorem standardLubinTateLevelCompleteDVF_hasUniqueDVFValuationExtension
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    RamificationTheory.DiscreteValuationField.DVF.HasUniqueValuationExtension.{u, v, u, 0, 0}
      F.toCompleteDVF.toDVF
      (standardLubinTateLevelCompleteDVF hπ n).toDVF