Module

FinitePlaceUnramifiedH1.lean

Nyll.SawinTotallyRealTowers.UnramifiedProPRelationRank.Local.FinitePlaceUnramifiedH1
12 declarations indexed from sourceView source ↗

Unramified degree-one characters at a finite place

The valuation-subring inertia group is pulled back to the chosen absolute decomposition group. Restriction to this inertia subgroup defines the unramified continuous H¹ subspace.

Declarations

ClassFieldTower.Martinet.Shafarevich.finitePlaceUnramifiedH1Module
Source context 9 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H))
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteValueExtension_nonarchimedean

The chosen absolute-value extension at a finite place is nonarchimedean.

Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
local instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
theorem finitePlaceAbsoluteValueExtension_nonarchimedean
    (v : HeightOneSpectrum (NumberField.RingOfIntegers F)) :
    LubinTate.Valuations.NonarchimedeanAbsoluteValue
      (finitePlaceAbsoluteValueExtension F v).1
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteValuationSubring

The valuation subring of the algebraic closure selected by the chosen finite place.

Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
local instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
abbrev finitePlaceAbsoluteValuationSubring
    (v : HeightOneSpectrum (NumberField.RingOfIntegers F)) :
    ValuationSubring (AlgebraicClosure F)
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteDecompositionValuationEquiv

The canonical comparison from the absolute decomposition group to its valuation-subring form.

Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
local instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
def finitePlaceAbsoluteDecompositionValuationEquiv
    (v : HeightOneSpectrum (NumberField.RingOfIntegers F)) :
    finitePlaceAbsoluteDecompositionGroup F v ≃*
      RamificationTheory.HilbertRamification.ValuationSubring.decompositionGroup F
        (finitePlaceAbsoluteValuationSubring F v)
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteInertiaSubgroup

Absolute inertia inside the chosen absolute decomposition group.

Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
local instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
abbrev finitePlaceAbsoluteInertiaSubgroup
    (v : HeightOneSpectrum (NumberField.RingOfIntegers F)) :
    Subgroup (finitePlaceAbsoluteDecompositionGroup F v)
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteInertiaInclusion

The continuous inclusion of absolute inertia into absolute decomposition.

Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
local instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
def finitePlaceAbsoluteInertiaInclusion
    (v : HeightOneSpectrum (NumberField.RingOfIntegers F)) :
    finitePlaceAbsoluteInertiaSubgroup F v →ₜ*
      finitePlaceAbsoluteDecompositionGroup F v
ClassFieldTower.Martinet.Shafarevich.finitePlaceAbsoluteInertiaInclusion_apply
Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
local instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
theorem finitePlaceAbsoluteInertiaInclusion_apply
    (v : HeightOneSpectrum (NumberField.RingOfIntegers F))
    (sigma : finitePlaceAbsoluteInertiaSubgroup F v) :
    finitePlaceAbsoluteInertiaInclusion F v sigma = sigma.1
ClassFieldTower.Martinet.Shafarevich.finitePlaceH1InertiaRestrictionAddHom

Restriction of continuous mod-p characters from decomposition to inertia.

Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
local instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
def finitePlaceH1InertiaRestrictionAddHom
    (v : HeightOneSpectrum (NumberField.RingOfIntegers F)) :
    ContinuousH1ZMod (p := p) (G := finitePlaceAbsoluteDecompositionGroup F v) →+
      ContinuousH1ZMod (p := p) (G := finitePlaceAbsoluteInertiaSubgroup F v) where
  toFun chi :=
    { toFun := fun sigma ↦ chi (Additive.ofMul sigma.toMul.1)
      map_zero' := chi.map_zero
      map_add' := fun sigma tau ↦ chi.map_add
        (Additive.ofMul sigma.toMul.1) (Additive.ofMul tau.toMul.1)
      continuous_toFun := chi.continuous_toFun.comp continuous_subtype_val }
  map_zero' := by
    ext sigma
    rfl
  map_add' := by
    intro chi psi
    ext sigma
    rfl
ClassFieldTower.Martinet.Shafarevich.finitePlaceH1InertiaRestriction

Linear restriction of continuous mod-p characters from decomposition to inertia.

Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
local instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
def finitePlaceH1InertiaRestriction
    (v : HeightOneSpectrum (NumberField.RingOfIntegers F)) :
    ContinuousH1ZMod (p := p) (G := finitePlaceAbsoluteDecompositionGroup F v) →ₗ[ZMod p]
      ContinuousH1ZMod (p := p) (G := finitePlaceAbsoluteInertiaSubgroup F v)
ClassFieldTower.Martinet.Shafarevich.finitePlaceH1InertiaRestriction_apply
Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
local instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
theorem finitePlaceH1InertiaRestriction_apply
    (v : HeightOneSpectrum (NumberField.RingOfIntegers F))
    (chi : ContinuousH1ZMod (p := p) (G := finitePlaceAbsoluteDecompositionGroup F v))
    (sigma : finitePlaceAbsoluteInertiaSubgroup F v) :
    finitePlaceH1InertiaRestriction F p v chi (Additive.ofMul sigma) =
      chi (Additive.ofMul sigma.1)
ClassFieldTower.Martinet.Shafarevich.finitePlaceUnramifiedH1

Continuous degree-one characters unramified at v: those trivial on absolute inertia.

Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
local instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
abbrev finitePlaceUnramifiedH1
    (v : HeightOneSpectrum (NumberField.RingOfIntegers F)) :
    Submodule (ZMod p)
      (ContinuousH1ZMod (p := p) (G := finitePlaceAbsoluteDecompositionGroup F v))
ClassFieldTower.Martinet.Shafarevich.mem_finitePlaceUnramifiedH1_iff
Source context 10 commands

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

open NumberField IsDedekindDomain
open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open ClassFieldTower.Cohomology
open ClassFieldTower.ProP
variable (F : Type) [Field F] [NumberField F]
variable (p : ℕ)
local instance finitePlaceUnramifiedH1Module
    {q : ℕ} {H : Type*} [Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
    Module (ZMod q) (ContinuousH1ZMod (p := q) (G := H)) :=
  continuousH1ZModModule
theorem mem_finitePlaceUnramifiedH1_iff
    (v : HeightOneSpectrum (NumberField.RingOfIntegers F))
    (chi : ContinuousH1ZMod (p := p) (G := finitePlaceAbsoluteDecompositionGroup F v)) :
    chi ∈ finitePlaceUnramifiedH1 F p v ↔
      ∀ sigma : finitePlaceAbsoluteInertiaSubgroup F v,
        chi (Additive.ofMul sigma.1) = 0