Module

Intertwiner.lean

Nyll.ClassFieldTheory.LubinTate.FormalModule.Intertwiner
7 declarations indexed from sourceView source ↗

Intertwining equations for Lubin--Tate series

For two Lubin--Tate series with the same prescribed linear coefficient, this module defines the multivariable intertwining equation and its additive defect.

Declarations

LubinTate.SameUniformizer.inVariable

Insert a one-variable Lubin--Tate series into the variable X_i.

Source context 8 commands

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

noncomputable section
universe u v
namespace LubinTate
namespace SameUniformizer
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
variable {F : LocalField.{u, v} K} {π : F.valuationSubring}
variable {σ : Type*}
def inVariable (e : LubinTateSeries F π) (i : σ) :
    MvPowerSeries σ F.valuationSubring
LubinTate.SameUniformizer.constantCoeff_inVariable

States the theorem constantCoeff_inVariable.

Source context 8 commands

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

noncomputable section
universe u v
namespace LubinTate
namespace SameUniformizer
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
variable {F : LocalField.{u, v} K} {π : F.valuationSubring}
variable {σ : Type*}
theorem constantCoeff_inVariable (e : LubinTateSeries F π) (i : σ) :
    MvPowerSeries.constantCoeff (inVariable e i) = 0
LubinTate.SameUniformizer.inVariable_hasSubst

The family i |-> e(X_i) admits genuine multivariable substitution.

Source context 8 commands

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

noncomputable section
universe u v
namespace LubinTate
namespace SameUniformizer
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
variable {F : LocalField.{u, v} K} {π : F.valuationSubring}
variable {σ : Type*}
theorem inVariable_hasSubst [Finite σ] (e : LubinTateSeries F π) :
    MvPowerSeries.HasSubst (fun i : σ ↦ inVariable e i) :=
  MvPowerSeries.hasSubst_of_constantCoeff_zero
    (fun i ↦ constantCoeff_inVariable e i)
LubinTate.SameUniformizer.Intertwines

The literal same-uniformizer equation e(H(X_i)) = H(ebar(X_i)).

Source context 8 commands

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

noncomputable section
universe u v
namespace LubinTate
namespace SameUniformizer
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
variable {F : LocalField.{u, v} K} {π : F.valuationSubring}
variable {σ : Type*}
def Intertwines (e ebar : LubinTateSeries F π)
    (H : MvPowerSeries σ F.valuationSubring) : Prop
LubinTate.SameUniformizer.defect

The coefficientwise defect whose vanishing is the intertwining equation.

Source context 8 commands

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

noncomputable section
universe u v
namespace LubinTate
namespace SameUniformizer
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
variable {F : LocalField.{u, v} K} {π : F.valuationSubring}
variable {σ : Type*}
def defect (e ebar : LubinTateSeries F π)
    (H : MvPowerSeries σ F.valuationSubring) :
    MvPowerSeries σ F.valuationSubring
LubinTate.SameUniformizer.intertwines_iff_defect_eq_zero

States the theorem intertwines_iff_defect_eq_zero.

Source context 8 commands

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

noncomputable section
universe u v
namespace LubinTate
namespace SameUniformizer
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
variable {F : LocalField.{u, v} K} {π : F.valuationSubring}
variable {σ : Type*}
theorem intertwines_iff_defect_eq_zero
    (e ebar : LubinTateSeries F π)
    (H : MvPowerSeries σ F.valuationSubring) :
    Intertwines e ebar H ↔ defect e ebar H = 0
LubinTate.SameUniformizer.intertwines_X

Each variable itself intertwines a Lubin--Tate series with itself.

Source context 8 commands

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

noncomputable section
universe u v
namespace LubinTate
namespace SameUniformizer
open LocalFieldTheory.DiscreteValuationField
variable {K : Type u} [Field K]
variable {F : LocalField.{u, v} K} {π : F.valuationSubring}
variable {σ : Type*}
theorem intertwines_X [Finite σ]
    (e : LubinTateSeries F π) (i : σ) :
    Intertwines e e (MvPowerSeries.X i)