Module

IntegerValuationUniformizer.lean

Nyll.ValuedFieldTheory.LocalField.DiscreteValuationField.ValuationSubringUnits.IntegerValuationUniformizer
7 declarations indexed from sourceView source ↗

Uniformizers and unit subgroups for induced integer valuations

This file relates the induced integer valuation to normalized uniformizers, valuation-ring units, and scalar extension of field units.

Declarations

LocalFieldTheory.DiscreteValuationField.MultiplicativeIntegerValuation.ofWithZeroValuation_isUniformizer_of_valuation_eq_exp_neg

An element of ℤᵐ⁰-value exp (-1) is a uniformizer for the attached integer-valued multiplicative valuation.

Source context 7 commands

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

noncomputable section
universe u
open WithZero
open scoped WithZero
namespace LocalFieldTheory.DiscreteValuationField
namespace MultiplicativeIntegerValuation
variable {K : Type u} [Field K]
theorem ofWithZeroValuation_isUniformizer_of_valuation_eq_exp_neg
    (v : _root_.Valuation K (WithZero (Multiplicative ℤ))) (π : Kˣ)
    (hπ : v (π : K) = WithZero.exp (-1 : ℤ)) :
    (ofWithZeroValuation v).IsUniformizer π
LocalFieldTheory.DiscreteValuationField.MultiplicativeIntegerValuation.ofWithZeroValuation_hasUniformizer_of_exists_valuation_eq_exp_neg

A normalized ℤᵐ⁰-valued valuation with an element of value exp (-1) has a uniformizer in the attached integer-valued multiplicative valuation.

Source context 7 commands

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

noncomputable section
universe u
open WithZero
open scoped WithZero
namespace LocalFieldTheory.DiscreteValuationField
namespace MultiplicativeIntegerValuation
variable {K : Type u} [Field K]
theorem ofWithZeroValuation_hasUniformizer_of_exists_valuation_eq_exp_neg
    (v : _root_.Valuation K (WithZero (Multiplicative ℤ)))
    (h : ∃ π : Kˣ, v (π : K) = WithZero.exp (-1 : ℤ)) :
    (ofWithZeroValuation v).HasUniformizer
LocalFieldTheory.DiscreteValuationField.MultiplicativeIntegerValuation.exists_unit_valuation_eq_exp_neg_of_surjective

A surjective ℤᵐ⁰-valued valuation has a field unit of value exp (-1).

Source context 7 commands

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

noncomputable section
universe u
open WithZero
open scoped WithZero
namespace LocalFieldTheory.DiscreteValuationField
namespace MultiplicativeIntegerValuation
variable {K : Type u} [Field K]
theorem exists_unit_valuation_eq_exp_neg_of_surjective
    (v : _root_.Valuation K (WithZero (Multiplicative ℤ))) (hv : Function.Surjective v) :
    ∃ π : Kˣ, v (π : K) = WithZero.exp (-1 : ℤ)
LocalFieldTheory.DiscreteValuationField.MultiplicativeIntegerValuation.ofWithZeroValuation_hasUniformizer_of_surjective

A surjective ℤᵐ⁰-valued valuation gives a uniformizer for the attached integer-valued multiplicative valuation.

Source context 7 commands

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

noncomputable section
universe u
open WithZero
open scoped WithZero
namespace LocalFieldTheory.DiscreteValuationField
namespace MultiplicativeIntegerValuation
variable {K : Type u} [Field K]
theorem ofWithZeroValuation_hasUniformizer_of_surjective
    (v : _root_.Valuation K (WithZero (Multiplicative ℤ))) (hv : Function.Surjective v) :
    (ofWithZeroValuation v).HasUniformizer
LocalFieldTheory.DiscreteValuationField.MultiplicativeIntegerValuation.ofWithZeroValuation_val_surjective_of_surjective

A surjective ℤᵐ⁰-valued valuation gives a surjective integer-valued valuation on field units.

Source context 7 commands

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

noncomputable section
universe u
open WithZero
open scoped WithZero
namespace LocalFieldTheory.DiscreteValuationField
namespace MultiplicativeIntegerValuation
variable {K : Type u} [Field K]
theorem ofWithZeroValuation_val_surjective_of_surjective
    (v : _root_.Valuation K (WithZero (Multiplicative ℤ))) (hv : Function.Surjective v) :
    Function.Surjective (ofWithZeroValuation v).val
LocalFieldTheory.DiscreteValuationField.MultiplicativeIntegerValuation.ofWithZeroValuation_zeroSubgroup_eq_unitGroup

Establishes the identity (ofWithZeroValuation v).zeroSubgroup = v.valuationSubring.unitGroup.

Source context 7 commands

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

noncomputable section
universe u
open WithZero
open scoped WithZero
namespace LocalFieldTheory.DiscreteValuationField
namespace MultiplicativeIntegerValuation
variable {K : Type u} [Field K]
theorem ofWithZeroValuation_zeroSubgroup_eq_unitGroup
    (v : _root_.Valuation K (WithZero (Multiplicative ℤ))) :
    (ofWithZeroValuation v).zeroSubgroup =
      v.valuationSubring.unitGroup
LocalFieldTheory.DiscreteValuationField.MultiplicativeIntegerValuation.baseUnitsMap_zeroSubgroup_ofWithZeroValuation

Establishes the membership statement ∀ u : Kˣ, u ∈ (ofWithZeroValuation vK).zeroSubgroup → baseUnitsMap (K := K) (L := L) u ∈ (ofWithZeroValuation vL).zeroSubgroup.

Source context 8 commands

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

noncomputable section
universe u
open WithZero
open scoped WithZero
namespace LocalFieldTheory.DiscreteValuationField
namespace MultiplicativeIntegerValuation
variable {K : Type u} [Field K]
variable {L : Type u} [Field L] [Algebra K L]
theorem baseUnitsMap_zeroSubgroup_ofWithZeroValuation
    (vK : _root_.Valuation K (WithZero (Multiplicative ℤ)))
    (vL : _root_.Valuation L (WithZero (Multiplicative ℤ))) [vK.HasExtension vL] :
    ∀ u : Kˣ, u ∈ (ofWithZeroValuation vK).zeroSubgroup →
      baseUnitsMap (K := K) (L := L) u ∈
        (ofWithZeroValuation vL).zeroSubgroup