Module

AlgebraicLocalizationTopology.lean

Nyll.ValuedFieldTheory.Ramification.HilbertRamification.AlgebraicLocalizationTopology
14 declarations indexed from sourceView source ↗

Topological decomposition--localization comparison

The algebraic localization comparison is algebraically a MulEquiv. This file establishes its finite-support continuity input: fixing one element of the algebraic localization only requires fixing finitely many elements of the original algebraic extension.

Declarations

ClassFieldTower.Martinet.Shafarevich.generalLocalizationBaseAlgebra
Source context 11 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion
ClassFieldTower.Martinet.Shafarevich.generalLocalizationBaseSMul
Source context 12 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
instance generalLocalizationBaseSMul : SMul K w.1.Completion
ClassFieldTower.Martinet.Shafarevich.generalLocalizationCompletionAlgebra
Source context 13 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion
ClassFieldTower.Martinet.Shafarevich.localization
Source context 14 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
local instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion :=
  AbsoluteValue.completionAlgebra vK w.1 w.2
abbrev localization
ClassFieldTower.Martinet.Shafarevich.algebraicLocalization_fixing_finite_support

The action on any one algebraic-localization element is controlled by finitely many elements of the original algebraic extension. This is the pointwise source for continuity of the decomposition--localization comparison in the Krull topologies.

Source context 15 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
local instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion :=
  AbsoluteValue.completionAlgebra vK w.1 w.2
omit [IsGalois K L] in
theorem algebraicLocalization_fixing_finite_support
    (z : localization vK w) :
    ∃ S : Finset L, ∀ σ : absoluteValueDecompositionGroup K w.1,
      (∀ x ∈ S, (σ.1 : L ≃ₐ[K] L) x = x) →
        decompositionGroupToLocalization vK hvK w σ z = z
ClassFieldTower.Martinet.Shafarevich.decompositionGroupToAlgebraicLocalizationMonoidHom

The algebraic decomposition--localization comparison as a monoid homomorphism.

Source context 14 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
local instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion :=
  AbsoluteValue.completionAlgebra vK w.1 w.2
def decompositionGroupToAlgebraicLocalizationMonoidHom :
    absoluteValueDecompositionGroup K w.1 →*
      (localization vK w ≃ₐ[vK.Completion] localization vK w)
ClassFieldTower.Martinet.Shafarevich.algEquiv_fix_of_fin_generates
Source context 14 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
local instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion :=
  AbsoluteValue.completionAlgebra vK w.1 w.2
theorem algEquiv_fix_of_fin_generates
    {F A : Type*} [Field F] [Field A] [Algebra F A]
    (E : IntermediateField F A) {n : ℕ} (b : Fin n → E)
    (hb : Submodule.span F (Set.range b) = ⊤)
    (sigma : A ≃ₐ[F] A)
    (hsigma : ∀ i, sigma (b i : A) = b i) (z : E) :
    sigma (z : A) = z
ClassFieldTower.Martinet.Shafarevich.absoluteValueDecompositionGroup_fixing_finset_mem_nhds
Source context 14 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
local instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion :=
  AbsoluteValue.completionAlgebra vK w.1 w.2
theorem absoluteValueDecompositionGroup_fixing_finset_mem_nhds
    (S : Finset L) :
    {sigma : absoluteValueDecompositionGroup K w.1 |
      ∀ x ∈ S, (sigma.1 : L ≃ₐ[K] L) x = x} ∈ 𝓝 1
ClassFieldTower.Martinet.Shafarevich.algebraicLocalizationStabilizerSubgroup

The subgroup of the decomposition group fixing one algebraic-localization element.

Source context 14 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
local instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion :=
  AbsoluteValue.completionAlgebra vK w.1 w.2
def algebraicLocalizationStabilizerSubgroup
    (z : localization vK w) :
    Subgroup (absoluteValueDecompositionGroup K w.1)
ClassFieldTower.Martinet.Shafarevich.mem_algebraicLocalizationStabilizerSubgroup_iff
Source context 14 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
local instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion :=
  AbsoluteValue.completionAlgebra vK w.1 w.2
theorem mem_algebraicLocalizationStabilizerSubgroup_iff
    (z : localization vK w) (sigma : absoluteValueDecompositionGroup K w.1) :
    sigma ∈ algebraicLocalizationStabilizerSubgroup vK hvK w z ↔
      decompositionGroupToAlgebraicLocalizationMonoidHom vK hvK w sigma z = z
ClassFieldTower.Martinet.Shafarevich.decompositionGroupToAlgebraicLocalization_stabilizer_isOpen

The stabilizer of one algebraic-localization element has open preimage in the decomposition group.

Source context 14 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
local instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion :=
  AbsoluteValue.completionAlgebra vK w.1 w.2
theorem decompositionGroupToAlgebraicLocalization_stabilizer_isOpen
    (z : localization vK w) :
    IsOpen (algebraicLocalizationStabilizerSubgroup vK hvK w z :
      Set (absoluteValueDecompositionGroup K w.1))
ClassFieldTower.Martinet.Shafarevich.decompositionGroupToAlgebraicLocalization_fixingSubgroup_mem_nhds

The preimage of a finite-stage fixing subgroup is a neighborhood of the identity in the decomposition group.

Source context 14 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
local instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion :=
  AbsoluteValue.completionAlgebra vK w.1 w.2
theorem decompositionGroupToAlgebraicLocalization_fixingSubgroup_mem_nhds
    (E : IntermediateField vK.Completion (localization vK w))
    [FiniteDimensional vK.Completion E] :
    {sigma : absoluteValueDecompositionGroup K w.1 |
        decompositionGroupToAlgebraicLocalizationMonoidHom vK hvK w sigma ∈
          E.fixingSubgroup} ∈ 𝓝 1
ClassFieldTower.Martinet.Shafarevich.decompositionGroupToAlgebraicLocalization_continuous

The decomposition--localization comparison is continuous for the two Krull topologies.

Source context 14 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
local instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion :=
  AbsoluteValue.completionAlgebra vK w.1 w.2
theorem decompositionGroupToAlgebraicLocalization_continuous :
    Continuous (decompositionGroupEquivAlgebraicLocalizationAut vK hvK w)
ClassFieldTower.Martinet.Shafarevich.decompositionGroupContinuousMulEquivAlgebraicLocalizationAut

The decomposition group and the algebraic-localization Galois group are canonically isomorphic as topological groups.

Source context 14 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open AlgebraicNumberTheory.Valuations
open HilbertRamification
open scoped Topology
universe u v
section GeneralLocalization
variable {K : Type u} {L : Type v} [Field K] [Field L] [Algebra K L]
variable [IsGalois K L]
variable (vK : AbsoluteValue K ℝ) (hvK : vK.IsNontrivial)
variable (w : AbsoluteValueExtension vK L)
local instance generalLocalizationBaseAlgebra : Algebra K w.1.Completion :=
  AbsoluteValue.extensionCompletionAlgebra (K := K) w.1
local instance generalLocalizationBaseSMul : SMul K w.1.Completion :=
  (AbsoluteValue.extensionCompletionAlgebra (K := K) w.1).toSMul
local instance generalLocalizationCompletionAlgebra :
    Algebra vK.Completion w.1.Completion :=
  AbsoluteValue.completionAlgebra vK w.1 w.2
def decompositionGroupContinuousMulEquivAlgebraicLocalizationAut :
    absoluteValueDecompositionGroup K w.1 ≃ₜ*
      (localization vK w ≃ₐ[vK.Completion] localization vK w)