Module

RealLowerRamificationGroupCanonical.lean

Nyll.ClassFieldTheory.Theorems.HasseArf.RealLowerRamificationGroupCanonical
1 declaration indexed from sourceView source ↗

Canonical real lower ramification groups

The real-index filtration is decreasing directly from the antitonicity of powers of the maximal ideal. No choice of a local extension is needed.

Imports5
Imported by2

Declarations

ClassFieldTheory.realLowerRamificationGroup_canonical_antitone

The public real lower groups of a finite Abelian local extension form a decreasing filtration of its canonical decomposition group.

Source context 3 commands

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

noncomputable section
namespace ClassFieldTheory
universe u v
theorem realLowerRamificationGroup_canonical_antitone
    (K : Type u) (L : Type v) [Field K] [Field L] [Algebra K L]
    [FiniteDimensional K L] [IsAbelianGalois K L]
    [ValuativeRel K] [TopologicalSpace K]
    [IsNonarchimedeanLocalField K]
    [ValuativeRel L] [TopologicalSpace L]
    [IsNonarchimedeanLocalField L]
    [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)] :
    Antitone (ClassFieldTheory.realLowerRamificationGroup K
      (ValuativeRel.valuation L).valuationSubring)