Module

CompletedPrimitiveIrreducible.lean

Nyll.ClassFieldTheory.LubinTate.EqualCharacteristic.CompletedLevel.CompletedPrimitiveIrreducible
11 declarations indexed from sourceView source ↗

The completed theta-intertwining theorem: irreducibility after completed unramified base change

The primitive Lubin--Tate polynomial remains Eisenstein after replacing the finite residue field κ by its algebraic closure. Consequently it remains irreducible over (AlgebraicClosure κ)((T)). This is the algebraic input needed to prescribe the image of a primitive point when arithmetic Frobenius is extended to the completed level field.

Declarations

LubinTate.EqualCharacteristic.equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
Source context 7 commands

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

noncomputable section
open scoped LaurentSeries Polynomial PowerSeries
universe u v
namespace LubinTate
namespace EqualCharacteristic
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
instance equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
    (F : LocalField.{u, v} K) :
    Algebra F.residueField⸨X⸩
      (equalCharacteristicCompletedUnramifiedField F.residueField)
LubinTate.EqualCharacteristic.equalCharacteristicCompletedIntegralPrimitivePolynomial

Coefficientwise extension of the integral primitive polynomial from κ[[T]] to (AlgebraicClosure κ)[[T]].

Source context 8 commands

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

noncomputable section
open scoped LaurentSeries Polynomial PowerSeries
universe u v
namespace LubinTate
namespace EqualCharacteristic
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
noncomputable local instance equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
    (F : LocalField.{u, v} K) :
    Algebra F.residueField⸨X⸩
      (equalCharacteristicCompletedUnramifiedField F.residueField) :=
  laurentSeriesCoefficientAlgebra
def equalCharacteristicCompletedIntegralPrimitivePolynomial
    (F : LocalField.{u, v} K) (n : ℕ) :
    Polynomial (AlgebraicClosure F.residueField)⟦X⟧
LubinTate.EqualCharacteristic.equalCharacteristicCompletedIntegralPrimitivePolynomial_monic

States the theorem equalCharacteristicCompletedIntegralPrimitivePolynomial_monic.

Source context 8 commands

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

noncomputable section
open scoped LaurentSeries Polynomial PowerSeries
universe u v
namespace LubinTate
namespace EqualCharacteristic
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
noncomputable local instance equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
    (F : LocalField.{u, v} K) :
    Algebra F.residueField⸨X⸩
      (equalCharacteristicCompletedUnramifiedField F.residueField) :=
  laurentSeriesCoefficientAlgebra
theorem equalCharacteristicCompletedIntegralPrimitivePolynomial_monic
    (F : LocalField.{u, v} K) (n : ℕ) :
    (equalCharacteristicCompletedIntegralPrimitivePolynomial F n).Monic
LubinTate.EqualCharacteristic.equalCharacteristicCompletedIntegralPrimitivePolynomial_natDegree

States the theorem equalCharacteristicCompletedIntegralPrimitivePolynomial_natDegree.

Source context 8 commands

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

noncomputable section
open scoped LaurentSeries Polynomial PowerSeries
universe u v
namespace LubinTate
namespace EqualCharacteristic
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
noncomputable local instance equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
    (F : LocalField.{u, v} K) :
    Algebra F.residueField⸨X⸩
      (equalCharacteristicCompletedUnramifiedField F.residueField) :=
  laurentSeriesCoefficientAlgebra
theorem equalCharacteristicCompletedIntegralPrimitivePolynomial_natDegree
    (F : LocalField.{u, v} K) (n : ℕ) :
    (equalCharacteristicCompletedIntegralPrimitivePolynomial F n).natDegree =
      (Nat.card F.residueField - 1) * Nat.card F.residueField ^ n
LubinTate.EqualCharacteristic.equalCharacteristicPowerSeriesLaurent_baseChange_commutes

The power-series coefficient map commutes with passage to Laurent series.

Source context 8 commands

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

noncomputable section
open scoped LaurentSeries Polynomial PowerSeries
universe u v
namespace LubinTate
namespace EqualCharacteristic
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
noncomputable local instance equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
    (F : LocalField.{u, v} K) :
    Algebra F.residueField⸨X⸩
      (equalCharacteristicCompletedUnramifiedField F.residueField) :=
  laurentSeriesCoefficientAlgebra
theorem equalCharacteristicPowerSeriesLaurent_baseChange_commutes
    (F : LocalField.{u, v} K) :
    (algebraMap (AlgebraicClosure F.residueField)⟦X⟧
        (equalCharacteristicCompletedUnramifiedField F.residueField)).comp
        (PowerSeries.map
          (algebraMap F.residueField (AlgebraicClosure F.residueField))) =
      (algebraMap F.residueField⸨X⸩
          (equalCharacteristicCompletedUnramifiedField F.residueField)).comp
        (algebraMap F.residueField⟦X⟧ F.residueField⸨X⸩)
LubinTate.EqualCharacteristic.equalCharacteristicCompletedIntegralPrimitivePolynomial_map

Passing the integral polynomial to the Laurent fraction field gives exactly the completed primitive polynomial.

Source context 8 commands

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

noncomputable section
open scoped LaurentSeries Polynomial PowerSeries
universe u v
namespace LubinTate
namespace EqualCharacteristic
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
noncomputable local instance equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
    (F : LocalField.{u, v} K) :
    Algebra F.residueField⸨X⸩
      (equalCharacteristicCompletedUnramifiedField F.residueField) :=
  laurentSeriesCoefficientAlgebra
theorem equalCharacteristicCompletedIntegralPrimitivePolynomial_map
    (F : LocalField.{u, v} K) (n : ℕ) :
    (equalCharacteristicCompletedIntegralPrimitivePolynomial F n).map
        (algebraMap (AlgebraicClosure F.residueField)⟦X⟧
          (equalCharacteristicCompletedUnramifiedField F.residueField)) =
      equalCharacteristicCompletedPrimitivePolynomial F n
LubinTate.EqualCharacteristic.equalCharacteristicCompletedIntegralPrimitivePolynomial_map_constantCoeff

Reduction modulo T is the single leading monomial.

Source context 8 commands

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

noncomputable section
open scoped LaurentSeries Polynomial PowerSeries
universe u v
namespace LubinTate
namespace EqualCharacteristic
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
noncomputable local instance equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
    (F : LocalField.{u, v} K) :
    Algebra F.residueField⸨X⸩
      (equalCharacteristicCompletedUnramifiedField F.residueField) :=
  laurentSeriesCoefficientAlgebra
theorem equalCharacteristicCompletedIntegralPrimitivePolynomial_map_constantCoeff
    (F : LocalField.{u, v} K) (n : ℕ) :
    (equalCharacteristicCompletedIntegralPrimitivePolynomial F n).map
        (PowerSeries.constantCoeff
          (R := AlgebraicClosure F.residueField)) =
      Polynomial.X ^
        ((Nat.card F.residueField - 1) * Nat.card F.residueField ^ n)
LubinTate.EqualCharacteristic.equalCharacteristicCompletedIntegralPrimitivePolynomial_coeff_zero

States the theorem equalCharacteristicCompletedIntegralPrimitivePolynomial_coeff_zero.

Source context 8 commands

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

noncomputable section
open scoped LaurentSeries Polynomial PowerSeries
universe u v
namespace LubinTate
namespace EqualCharacteristic
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
noncomputable local instance equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
    (F : LocalField.{u, v} K) :
    Algebra F.residueField⸨X⸩
      (equalCharacteristicCompletedUnramifiedField F.residueField) :=
  laurentSeriesCoefficientAlgebra
theorem equalCharacteristicCompletedIntegralPrimitivePolynomial_coeff_zero
    (F : LocalField.{u, v} K) (n : ℕ) :
    (equalCharacteristicCompletedIntegralPrimitivePolynomial F n).coeff 0 =
      (PowerSeries.X : (AlgebraicClosure F.residueField)⟦X⟧)
LubinTate.EqualCharacteristic.equalCharacteristicCompletedIntegralPrimitivePolynomial_isEisensteinAt

The completed integral primitive polynomial is Eisenstein at (T).

Source context 8 commands

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

noncomputable section
open scoped LaurentSeries Polynomial PowerSeries
universe u v
namespace LubinTate
namespace EqualCharacteristic
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
noncomputable local instance equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
    (F : LocalField.{u, v} K) :
    Algebra F.residueField⸨X⸩
      (equalCharacteristicCompletedUnramifiedField F.residueField) :=
  laurentSeriesCoefficientAlgebra
theorem equalCharacteristicCompletedIntegralPrimitivePolynomial_isEisensteinAt
    (F : LocalField.{u, v} K) (n : ℕ) :
    (equalCharacteristicCompletedIntegralPrimitivePolynomial F n).IsEisensteinAt
      (Ideal.span
        ({PowerSeries.X} :
          Set (AlgebraicClosure F.residueField)⟦X⟧))
LubinTate.EqualCharacteristic.equalCharacteristicCompletedIntegralPrimitivePolynomial_irreducible

States the theorem equalCharacteristicCompletedIntegralPrimitivePolynomial_irreducible.

Source context 8 commands

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

noncomputable section
open scoped LaurentSeries Polynomial PowerSeries
universe u v
namespace LubinTate
namespace EqualCharacteristic
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
noncomputable local instance equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
    (F : LocalField.{u, v} K) :
    Algebra F.residueField⸨X⸩
      (equalCharacteristicCompletedUnramifiedField F.residueField) :=
  laurentSeriesCoefficientAlgebra
theorem equalCharacteristicCompletedIntegralPrimitivePolynomial_irreducible
    (F : LocalField.{u, v} K) (n : ℕ) :
    Irreducible (equalCharacteristicCompletedIntegralPrimitivePolynomial F n)
LubinTate.EqualCharacteristic.equalCharacteristicCompletedPrimitivePolynomial_irreducible

The primitive polynomial remains irreducible over the completed maximal unramified Laurent field.

Source context 8 commands

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

noncomputable section
open scoped LaurentSeries Polynomial PowerSeries
universe u v
namespace LubinTate
namespace EqualCharacteristic
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
noncomputable local instance equalCharacteristicCompletedPrimitiveIrreducibleBaseAlgebra
    (F : LocalField.{u, v} K) :
    Algebra F.residueField⸨X⸩
      (equalCharacteristicCompletedUnramifiedField F.residueField) :=
  laurentSeriesCoefficientAlgebra
theorem equalCharacteristicCompletedPrimitivePolynomial_irreducible
    (F : LocalField.{u, v} K) (n : ℕ) :
    Irreducible (equalCharacteristicCompletedPrimitivePolynomial F n)