Module

NormalBasisLattice.lean

Nyll.GaloisCohomology.Cyclic.Herbrand.NormalBasisLattice
126 declarations indexed from sourceView source ↗

Provides the public normal-basis lattice declarations used in Herbrand computations.

Additive quotient boundary

Declarations

CyclicCohomology.normalBasisConjugates_span_eq_top

The Gal(L/K) orbit of Mathlib's normal-basis generator spans L over K.

Source context 7 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
theorem normalBasisConjugates_span_eq_top :
    Submodule.span K
        (Set.range (fun σ : Gal(L/K) =>
          σ (IsGalois.normalBasis K L (1 : Gal(L/K))))) = ⊤ := by
  have hset :
      Set.range (fun σ : Gal(L/K) =>
        σ (IsGalois.normalBasis K L (1 : Gal(L/K)))) =
        Set.range (IsGalois.normalBasis K L) := by
    ext x
    constructor
    · rintro ⟨σ, rfl⟩
      exact ⟨σ, IsGalois.normalBasis_apply (K := K) (L := L) σ⟩
    · rintro ⟨σ, rfl⟩
      exact ⟨σ, (IsGalois.normalBasis_apply (K := K) (L := L) σ).symm⟩
  rw [hset]
  exact (IsGalois.normalBasis K L).span_eq
CyclicCohomology.chosenNormalBasisIntegerLattice

The classical normal-basis lattice candidate M: the 𝒪_K-span of the normal-basis orbit. Bounds comparing this lattice with 𝒪_L are deliberately made explicit in the lattice-comparison theorems below.

Source context 8 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
def chosenNormalBasisIntegerLattice : Submodule 𝒪[K] L
CyclicCohomology.chosenNormalBasisIntegerLattice_eq_span

Public characterization of the chosen normal-basis lattice as the span of the chosen generator's Galois orbit.

Source context 8 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
theorem chosenNormalBasisIntegerLattice_eq_span :
    chosenNormalBasisIntegerLattice K L =
      Submodule.span 𝒪[K]
        (Set.range (fun σ : Gal(L/K) =>
          σ (IsGalois.normalBasis K L (1 : Gal(L/K))))) :=
  rfl
CyclicCohomology.normalBasis_mem_integerLattice

Every normal-basis vector lies in the 𝒪_K-span lattice M.

Source context 8 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
theorem normalBasis_mem_integerLattice (σ : Gal(L/K)) :
    IsGalois.normalBasis K L σ ∈ chosenNormalBasisIntegerLattice K L
CyclicCohomology.normalBasis_one_mem_integerLattice

Mathlib's normal-basis generator lies in the 𝒪_K-span lattice M.

Source context 8 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
theorem normalBasis_one_mem_integerLattice :
    IsGalois.normalBasis K L (1 : Gal(L/K)) ∈
      chosenNormalBasisIntegerLattice K L
CyclicCohomology.chosenNormalBasisIntegerLattice_field_span_eq_top

After extending scalars back to K, the normal-basis lattice spans all of L.

Source context 8 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
theorem chosenNormalBasisIntegerLattice_field_span_eq_top :
    Submodule.span K ((chosenNormalBasisIntegerLattice K L : Submodule 𝒪[K] L) : Set L) =
      ⊤
CyclicCohomology.galoisGroup_apply_mem_chosenNormalBasisIntegerLattice

The normal-basis lattice M is stable under the actual Gal(L/K) action.

Source context 8 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
theorem galoisGroup_apply_mem_chosenNormalBasisIntegerLattice
    (τ : Gal(L/K)) {x : L}
    (hx : x ∈ chosenNormalBasisIntegerLattice K L) :
    τ x ∈ chosenNormalBasisIntegerLattice K L
CyclicCohomology.chosenNormalBasisIntegerLattice_fg

The normal-basis lattice M is finitely generated over 𝒪_K.

Source context 8 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
theorem chosenNormalBasisIntegerLattice_fg :
    (chosenNormalBasisIntegerLattice K L).FG
CyclicCohomology.baseIntegerScalarMulLinearMap

Multiplication by a base integer-ring element, as an 𝒪_K-linear endomorphism of the extension field.

Source context 8 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
def baseIntegerScalarMulLinearMap (a : 𝒪[K]) : L →ₗ[𝒪[K]] L where
  toFun x := algebraMap 𝒪[K] L a * x
  map_add' := by
    intro x y
    rw [mul_add]
  map_smul' := by
    intro r x
    simp [Algebra.smul_def, mul_comm, mul_left_comm]
CyclicCohomology.baseIntegerScalarMulLinearMap_apply

Evaluates the linear map given by scalar multiplication from the base integer ring.

Source context 9 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem baseIntegerScalarMulLinearMap_apply (a : 𝒪[K]) (x : L) :
    baseIntegerScalarMulLinearMap K L a x = algebraMap 𝒪[K] L a * x
CyclicCohomology.baseIntegerScalarMulSubmodule

The image of an 𝒪_K-submodule under multiplication by a base integer-ring element.

Source context 8 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
def baseIntegerScalarMulSubmodule (a : 𝒪[K]) (N : Submodule 𝒪[K] L) :
    Submodule 𝒪[K] L
CyclicCohomology.mem_baseIntegerScalarMulSubmodule_iff

Characterizes membership in the submodule generated by base-integer scalar multiples.

Source context 9 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem mem_baseIntegerScalarMulSubmodule_iff
    (a : 𝒪[K]) (N : Submodule 𝒪[K] L) (x : L) :
    x ∈ baseIntegerScalarMulSubmodule K L a N ↔
      ∃ y : L, y ∈ N ∧ algebraMap 𝒪[K] L a * y = x
CyclicCohomology.baseIntegerScalarMulSubmodule_fg_of_fg

Scalar multiplication by base integers preserves finite generation of submodules.

Source context 9 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem baseIntegerScalarMulSubmodule_fg_of_fg
    (a : 𝒪[K]) {N : Submodule 𝒪[K] L} (hN : N.FG) :
    (baseIntegerScalarMulSubmodule K L a N).FG
CyclicCohomology.chosenBaseUniformizerPowSubmodule

Multiplication of an 𝒪_K-submodule by a power of the chosen base uniformizer. The name deliberately records the construction's dependence on chosenIntegerRingUniformizer K; no uniformizer-independence result is part of this API. This is the concrete shape of the π_K^n lattices used in the local class-field-axiom calculation.

Source context 9 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
def chosenBaseUniformizerPowSubmodule (n : Nat) (N : Submodule 𝒪[K] L) :
    Submodule 𝒪[K] L
CyclicCohomology.mem_chosenBaseUniformizerPowSubmodule_iff

Characterizes membership in a chosen uniformizer-power submodule.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem mem_chosenBaseUniformizerPowSubmodule_iff
    (n : Nat) (N : Submodule 𝒪[K] L) (x : L) :
    x ∈ chosenBaseUniformizerPowSubmodule K L n N ↔
      ∃ y : L, y ∈ N ∧
        algebraMap 𝒪[K] L (chosenIntegerRingUniformizer K ^ n) * y = x
CyclicCohomology.chosenBaseUniformizerPowSubmodule_fg_of_fg

Multiplication by a chosen uniformizer power preserves finite generation.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem chosenBaseUniformizerPowSubmodule_fg_of_fg
    (n : Nat) {N : Submodule 𝒪[K] L} (hN : N.FG) :
    (chosenBaseUniformizerPowSubmodule K L n N).FG
CyclicCohomology.chosenBaseUniformizerPow_mul_mem_mono

Increasing the base-uniformizer exponent preserves membership after denominator clearing.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem chosenBaseUniformizerPow_mul_mem_mono
    {M : Submodule 𝒪[K] L} {m n : Nat} {x : L} (hmn : m ≤ n)
    (hx : algebraMap 𝒪[K] L (chosenIntegerRingUniformizer K ^ m) * x ∈ M) :
    algebraMap 𝒪[K] L (chosenIntegerRingUniformizer K ^ n) * x ∈ M
CyclicCohomology.chosenBaseUniformizerPowSubmodule_antitone

The lattices π_K^n N form a descending filtration.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem chosenBaseUniformizerPowSubmodule_antitone
    (N : Submodule 𝒪[K] L) {m n : Nat} (hmn : m ≤ n) :
    chosenBaseUniformizerPowSubmodule K L n N ≤
      chosenBaseUniformizerPowSubmodule K L m N
CyclicCohomology.chosenBaseUniformizerPowSubmodule_succ_le

Successive chosen uniformizer-power submodules form a descending chain.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem chosenBaseUniformizerPowSubmodule_succ_le
    (n : Nat) (N : Submodule 𝒪[K] L) :
    chosenBaseUniformizerPowSubmodule K L (n + 1) N ≤
      chosenBaseUniformizerPowSubmodule K L n N
CyclicCohomology.chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_fg

Every chosen uniformizer-power normal-basis lattice is finitely generated.

Source context 9 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
theorem chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_fg (n : Nat) :
    (chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)).FG
CyclicCohomology.exists_chosenBaseUniformizerPow_mul_mem_of_field_span_eq_top

If an 𝒪_K-submodule spans L after extending scalars to K, then every element of L enters that submodule after multiplying by a high enough power of the base prime element. The scalar-denominator step is exactly the local DVR denominator clearing in IdealQuotients.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem exists_chosenBaseUniformizerPow_mul_mem_of_field_span_eq_top
    {M : Submodule 𝒪[K] L}
    (hMspan : Submodule.span K ((M : Set L)) = ⊤) (x : L) :
    ∃ n : Nat, algebraMap 𝒪[K] L (chosenIntegerRingUniformizer K ^ n) * x ∈ M
CyclicCohomology.exists_chosenBaseUniformizerPowSubmodule_le_of_fg_of_field_span_eq_top

Finite-generation version of exists_chosenBaseUniformizerPow_mul_mem_of_field_span_eq_top: one exponent works for all elements of a finitely generated 𝒪_K-submodule.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem exists_chosenBaseUniformizerPowSubmodule_le_of_fg_of_field_span_eq_top
    {M N : Submodule 𝒪[K] L} (hN : N.FG)
    (hMspan : Submodule.span K ((M : Set L)) = ⊤) :
    ∃ n : Nat, chosenBaseUniformizerPowSubmodule K L n N ≤ M
CyclicCohomology.exists_chosenBaseUniformizerPow_mul_mul_mem_of_fg_of_field_span_eq_top

Product-denominator bound for multiplicative lattice control. If N and P are finitely generated 𝒪_K-submodules and M spans L after inverting 𝒪_K, then one power of the base prime element sends every product xy, x ∈ N, y ∈ P, back into M.

This is the multiplicative source needed before proving that 1 + π_K^n M is closed under multiplication for large n.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem exists_chosenBaseUniformizerPow_mul_mul_mem_of_fg_of_field_span_eq_top
    {M N P : Submodule 𝒪[K] L} (hN : N.FG) (hP : P.FG)
    (hMspan : Submodule.span K ((M : Set L)) = ⊤) :
    ∃ n : Nat, ∀ x : L, x ∈ N → ∀ y : L, y ∈ P →
      algebraMap 𝒪[K] L (chosenIntegerRingUniformizer K ^ n) * (x * y) ∈ M
CyclicCohomology.exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_mul_mul_mem

A sufficiently deep uniformizer-power normal-basis lattice absorbs the indicated products.

Source context 9 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
theorem exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_mul_mul_mem :
    ∃ n : Nat, ∀ x : L, x ∈ chosenNormalBasisIntegerLattice K L →
      ∀ y : L, y ∈ chosenNormalBasisIntegerLattice K L →
        algebraMap 𝒪[K] L (chosenIntegerRingUniformizer K ^ n) * (x * y) ∈
          chosenNormalBasisIntegerLattice K L
CyclicCohomology.exists_chosenBaseUniformizerPowSubmodule_mul_mul_mem_self_of_fg_of_field_span_eq_top

For sufficiently large n, the lattice π_K^n M is closed under multiplication. It supplies the multiplicative closure of 1 + π_K^n M in the principal-unit lattice.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem exists_chosenBaseUniformizerPowSubmodule_mul_mul_mem_self_of_fg_of_field_span_eq_top
    {M : Submodule 𝒪[K] L} (hMfg : M.FG)
    (hMspan : Submodule.span K ((M : Set L)) = ⊤) :
    ∃ c : Nat, ∀ n : Nat, c ≤ n → ∀ x : L,
      x ∈ chosenBaseUniformizerPowSubmodule K L n M →
      ∀ y : L, y ∈ chosenBaseUniformizerPowSubmodule K L n M →
        x * y ∈ chosenBaseUniformizerPowSubmodule K L n M
CyclicCohomology.exists_chosenBaseUniformizerPowSubmodule_mul_mul_mem_succ_of_fg_of_field_span_eq_top

For sufficiently large n, products of two elements of π_K^n M land in the next lattice step π_K^(n+1) M.

This is the product-depth estimate needed before the map V^n/V^(n+1) -> π_K^nM/π_K^(n+1)M can be made well-defined.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem exists_chosenBaseUniformizerPowSubmodule_mul_mul_mem_succ_of_fg_of_field_span_eq_top
    {M : Submodule 𝒪[K] L} (hMfg : M.FG)
    (hMspan : Submodule.span K ((M : Set L)) = ⊤) :
    ∃ c : Nat, ∀ n : Nat, c ≤ n → ∀ x : L,
      x ∈ chosenBaseUniformizerPowSubmodule K L n M →
      ∀ y : L, y ∈ chosenBaseUniformizerPowSubmodule K L n M →
        x * y ∈ chosenBaseUniformizerPowSubmodule K L (n + 1) M
CyclicCohomology.exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_mul_mul_mem_self

A sufficiently deep uniformizer-power normal-basis lattice is closed under the indicated self-products.

Source context 9 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
theorem exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_mul_mul_mem_self :
    ∃ c : Nat, ∀ n : Nat, c ≤ n → ∀ x : L,
      x ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
      ∀ y : L,
        y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
          x * y ∈
            chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_mul_mul_mem_succ

A sufficiently deep lattice sends the indicated products into the next uniformizer level.

Source context 9 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
theorem exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_mul_mul_mem_succ :
    ∃ c : Nat, ∀ n : Nat, c ≤ n → ∀ x : L,
      x ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
      ∀ y : L,
        y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
          x * y ∈
            chosenBaseUniformizerPowSubmodule K L (n + 1) (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.submodule_pow_succ_mem_of_mul_closed

Powers of an element stay in a multiplicatively closed additive lattice.

This is the finite algebraic input to the geometric-series inverse argument; completeness supplies the limit of these finite approximations.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] in
theorem submodule_pow_succ_mem_of_mul_closed
    {E : Submodule 𝒪[K] L}
    (hmul : ∀ x : L, x ∈ E → ∀ y : L, y ∈ E → x * y ∈ E)
    {x : L} (hx : x ∈ E) :
    ∀ m : Nat, x ^ (m + 1) ∈ E
CyclicCohomology.inverseCorrectionPartialSum

The finite inverse-correction sum (-x) + (-x)^2 + ... + (-x)^d.

When x is topologically nilpotent and the lattice is complete, these are the finite approximations to (1+x)⁻¹ - 1.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
def inverseCorrectionPartialSum (x : L) (d : Nat) : L
CyclicCohomology.inverseCorrectionPartialSum_zero

The zeroth inverse-correction partial sum is its initial term.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem inverseCorrectionPartialSum_zero (x : L) :
    inverseCorrectionPartialSum (L := L) x 0 = 0
CyclicCohomology.inverseCorrectionPartialSum_succ

Expands the inverse-correction partial sum at a successor index.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem inverseCorrectionPartialSum_succ (x : L) (d : Nat) :
    inverseCorrectionPartialSum (L := L) x (d + 1) =
      inverseCorrectionPartialSum (L := L) x d + (-x) ^ (d + 1)
CyclicCohomology.one_add_inverseCorrectionPartialSum_eq_geom_sum

Adding 1 turns the inverse-correction sum into the usual finite geometric sum with ratio -x.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem one_add_inverseCorrectionPartialSum_eq_geom_sum (x : L) (d : Nat) :
    1 + inverseCorrectionPartialSum (L := L) x d =
      (Finset.range (d + 1)).sum fun i => (-x) ^ i := by
  induction d with
  | zero =>
      simp [inverseCorrectionPartialSum]
  | succ d ih =>
      rw [inverseCorrectionPartialSum_succ, Finset.sum_range_succ, ← ih]
      simp [add_assoc]
CyclicCohomology.one_add_mul_one_add_inverseCorrectionPartialSum

Finite geometric inverse identity for the approximants to (1+x)⁻¹.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem one_add_mul_one_add_inverseCorrectionPartialSum (x : L) (d : Nat) :
    (1 + x) * (1 + inverseCorrectionPartialSum (L := L) x d) =
      1 - (-x) ^ (d + 1)
CyclicCohomology.one_add_mul_one_add_inverseCorrectionPartialSum_sub_one

The residual error after applying a finite inverse correction.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem one_add_mul_one_add_inverseCorrectionPartialSum_sub_one
    (x : L) (d : Nat) :
    (1 + x) * (1 + inverseCorrectionPartialSum (L := L) x d) - 1 =
      -((-x) ^ (d + 1))
CyclicCohomology.inverseCorrectionPartialSum_mem_of_mul_closed

Inverse-correction partial sums remain in any additive set closed under multiplication.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] in
theorem inverseCorrectionPartialSum_mem_of_mul_closed
    {E : Submodule 𝒪[K] L}
    (hmul : ∀ x : L, x ∈ E → ∀ y : L, y ∈ E → x * y ∈ E)
    {x : L} (hx : x ∈ E) (d : Nat) :
    inverseCorrectionPartialSum (L := L) x d ∈ E
CyclicCohomology.inverseCorrectionPartialProductError_mem_of_mul_closed

A finite inverse correction kills 1+x modulo the same multiplicatively closed additive lattice.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] in
theorem inverseCorrectionPartialProductError_mem_of_mul_closed
    {E : Submodule 𝒪[K] L}
    (hmul : ∀ x : L, x ∈ E → ∀ y : L, y ∈ E → x * y ∈ E)
    {x : L} (hx : x ∈ E) (d : Nat) :
    (1 + x) * (1 + inverseCorrectionPartialSum (L := L) x d) - 1 ∈ E
CyclicCohomology.submodule_isOpen_of_mem_nhds_zero

An additive 𝒪_K-submodule containing a neighborhood of 0 is open.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] in
theorem submodule_isOpen_of_mem_nhds_zero
    [TopologicalSpace L] [IsTopologicalAddGroup L]
    {E : Submodule 𝒪[K] L} (hE : (E : Set L) ∈ nhds (0 : L)) :
    IsOpen (E : Set L)
CyclicCohomology.submodule_isClosed_of_isOpen

An open additive 𝒪_K-submodule is closed.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] in
theorem submodule_isClosed_of_isOpen
    [TopologicalSpace L] [IsTopologicalAddGroup L]
    {E : Submodule 𝒪[K] L} (hE : IsOpen (E : Set L)) :
    IsClosed (E : Set L)
CyclicCohomology.submodule_isClosed_of_mem_nhds_zero

A neighborhood submodule is closed in a topological additive group.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] in
theorem submodule_isClosed_of_mem_nhds_zero
    [TopologicalSpace L] [IsTopologicalAddGroup L]
    {E : Submodule 𝒪[K] L} (hE : (E : Set L) ∈ nhds (0 : L)) :
    IsClosed (E : Set L)
CyclicCohomology.submodule_mem_of_tendsto_of_forall_mem_of_closed

If every term of a convergent sequence lies in a closed submodule, then the limit lies in that submodule.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
omit [FiniteDimensional K L] [IsGalois K L]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] in
theorem submodule_mem_of_tendsto_of_forall_mem_of_closed
    [TopologicalSpace L] {E : Submodule 𝒪[K] L} {f : Nat → L} {x : L}
    (hclosed : IsClosed (E : Set L)) (hf : Tendsto f atTop (nhds x))
    (hmem : ∀ d : Nat, f d ∈ E) :
    x ∈ E
CyclicCohomology.integerRingMap_uniformizer_mem_maximalIdeal_of_valuationExtension

Under a valuation extension, the chosen base prime element maps into the maximal ideal of the extension valuation ring.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem integerRingMap_uniformizer_mem_maximalIdeal_of_valuationExtension :
    integerRingMapOfValuationExtension K L (chosenIntegerRingUniformizer K) ∈
      (𝓂[L] : Ideal 𝒪[L])
CyclicCohomology.exists_chosenBaseUniformizerPow_mul_mem_integerRing_of_valuationExtension

Extension-field denominator clearing by powers of the base prime element.

For any x : L, a sufficiently high power of the chosen prime element of 𝒪[K], mapped to L, sends x into 𝒪[L]. This is the denominator-clearing input used before comparing the normal-basis lattice with 𝒪_L: it uses only the DVR structure of 𝒪_L and the fact that the image of the base prime lies in 𝓂_L.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem exists_chosenBaseUniformizerPow_mul_mem_integerRing_of_valuationExtension
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] (x : L) :
    ∃ n : Nat,
      algebraMap 𝒪[K] L (chosenIntegerRingUniformizer K ^ n) * x ∈ 𝒪[L]
CyclicCohomology.integerRingToFieldLinearMap

The inclusion 𝒪_L -> L as an 𝒪_K-linear map, using the valuation-extension map 𝒪_K -> 𝒪_L for the scalar action.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def integerRingToFieldLinearMap : 𝒪[L] →ₗ[𝒪[K]] L where
  toFun x := (x : L)
  map_add' := by
    intro x y
    rfl
  map_smul' := by
    intro a x
    rfl
CyclicCohomology.integerRingFieldSubmodule

The valuation integer ring of L, viewed as an 𝒪_K-submodule of L. This is the 𝒪_L lattice compared with the normal-basis lattice.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def integerRingFieldSubmodule : Submodule 𝒪[K] L where
  carrier := {x | x ∈ 𝒪[L]}
  zero_mem' := by
    change (0 : L) ∈ 𝒪[L]
    exact zero_mem _
  add_mem' := by
    intro x y hx hy
    change x + y ∈ 𝒪[L]
    exact add_mem hx hy
  smul_mem' := by
    intro a x hx
    change a • x ∈ 𝒪[L]
    rw [Algebra.smul_def]
    have ha : algebraMap 𝒪[K] L a ∈ 𝒪[L] := by
      change algebraMap K L (a : K) ∈ 𝒪[L]
      exact (integerRingMapOfValuationExtension K L a).2
    exact mul_mem ha hx
CyclicCohomology.mem_integerRingFieldSubmodule_iff

Characterizes the field elements lying in the embedded integer-ring submodule.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] [TopologicalSpace K]
  [IsNonarchimedeanLocalField K] in
theorem mem_integerRingFieldSubmodule_iff (x : L) :
    x ∈ integerRingFieldSubmodule K L ↔ x ∈ 𝒪[L]
CyclicCohomology.integerRing_mem_integerRingFieldSubmodule

Every integer-ring element lies in the corresponding field submodule.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] [TopologicalSpace K]
  [IsNonarchimedeanLocalField K] in
theorem integerRing_mem_integerRingFieldSubmodule (x : 𝒪[L]) :
    (x : L) ∈ integerRingFieldSubmodule K L
CyclicCohomology.chosenBaseUniformizerPow_integerRingFieldSubmodule_mem_nhds_zero

A base-uniformizer multiple of 𝒪_L is a zero-neighborhood in L.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem chosenBaseUniformizerPow_integerRingFieldSubmodule_mem_nhds_zero
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] (m : Nat) :
    ((chosenBaseUniformizerPowSubmodule K L m
      (integerRingFieldSubmodule K L) : Set L)) ∈ nhds (0 : L)
CyclicCohomology.maximalIdealFieldSubmodule

The maximal ideal 𝓂_L, viewed inside L as an 𝒪_K-submodule.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] [TopologicalSpace K]
  [IsNonarchimedeanLocalField K] in
def maximalIdealFieldSubmodule : Submodule 𝒪[K] L where
  carrier := {x | ∃ a : 𝒪[L], a ∈ (𝓂[L] : Ideal 𝒪[L]) ∧ (a : L) = x}
  zero_mem' := by
    refine ⟨0, by simp, by simp⟩
  add_mem' := by
    intro x y hx hy
    rcases hx with ⟨a, ha, rfl⟩
    rcases hy with ⟨b, hb, rfl⟩
    refine ⟨a + b, (𝓂[L] : Ideal 𝒪[L]).add_mem ha hb, by simp⟩
  smul_mem' := by
    intro c x hx
    rcases hx with ⟨a, ha, rfl⟩
    refine ⟨integerRingMapOfValuationExtension K L c * a, ?_, ?_⟩
    · exact Ideal.mul_mem_left _ (integerRingMapOfValuationExtension K L c) ha
    · change ((integerRingMapOfValuationExtension K L c : 𝒪[L]) : L) * (a : L) =
        c • (a : L)
      rw [Algebra.smul_def]
      congr 1
CyclicCohomology.mem_maximalIdealFieldSubmodule_iff

Characterizes membership in the field submodule induced by the maximal ideal.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] [TopologicalSpace K]
  [IsNonarchimedeanLocalField K] in
theorem mem_maximalIdealFieldSubmodule_iff (x : L) :
    x ∈ maximalIdealFieldSubmodule K L ↔
      ∃ a : 𝒪[L], a ∈ (𝓂[L] : Ideal 𝒪[L]) ∧ (a : L) = x
CyclicCohomology.maximalIdealFieldSubmodule_le_integerRingFieldSubmodule

The maximal-ideal field submodule is contained in the integer-ring field submodule.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] [TopologicalSpace K]
  [IsNonarchimedeanLocalField K] in
theorem maximalIdealFieldSubmodule_le_integerRingFieldSubmodule :
    maximalIdealFieldSubmodule K L ≤ integerRingFieldSubmodule K L
CyclicCohomology.exists_chosenBaseUniformizerPowSubmodule_le_integerRingFieldSubmodule_of_fg

A finitely generated 𝒪_K-submodule of L is sent into 𝒪_L after multiplication by a single sufficiently high power of the base prime element.

This proves the π_K^b N ≤ 𝒪_L first direction of the lattice-bound statement for any finitely generated N; applying it to the normal-basis lattice gives the needed denominator bound for M.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem exists_chosenBaseUniformizerPowSubmodule_le_integerRingFieldSubmodule_of_fg
    [TopologicalSpace L] [IsNonarchimedeanLocalField L]
    {N : Submodule 𝒪[K] L} (hN : N.FG) :
    ∃ n : Nat,
      chosenBaseUniformizerPowSubmodule K L n N ≤ integerRingFieldSubmodule K L
CyclicCohomology.exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_le_integerRingFieldSubmodule

Some uniformizer-power normal-basis lattice lies inside the integer-ring field submodule.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_le_integerRingFieldSubmodule
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] :
    ∃ n : Nat,
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
        integerRingFieldSubmodule K L
CyclicCohomology.chosenBaseUniformizerPowSubmodule_add_le_chosenBaseUniformizerPowSubmodule_of_le

Multiplying an existing containment by a further base-uniformizer power.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenBaseUniformizerPowSubmodule_add_le_chosenBaseUniformizerPowSubmodule_of_le
    {N M : Submodule 𝒪[K] L} {a n : Nat}
    (h : chosenBaseUniformizerPowSubmodule K L a N ≤ M) :
    chosenBaseUniformizerPowSubmodule K L (a + n) N ≤
      chosenBaseUniformizerPowSubmodule K L n M
CyclicCohomology.chosenBaseUniformizerPowSubmodule_succ_le_maximalIdealFieldSubmodule_of_le_integerRingFieldSubmodule

If π_K^b N is integral, then π_K^(b+1) N lands in the maximal ideal of 𝒪_L.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem
chosenBaseUniformizerPowSubmodule_succ_le_maximalIdealFieldSubmodule_of_le_integerRingFieldSubmodule
    {N : Submodule 𝒪[K] L} {b : Nat}
    (hb : chosenBaseUniformizerPowSubmodule K L b N ≤ integerRingFieldSubmodule K L) :
    chosenBaseUniformizerPowSubmodule K L (b + 1) N ≤
      maximalIdealFieldSubmodule K L
CyclicCohomology.exists_chosenBaseUniformizerPowSubmodule_le_maximalIdealFieldSubmodule_of_fg

A finitely generated submodule has a sufficiently deep uniformizer multiple inside the maximal ideal.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] in
theorem exists_chosenBaseUniformizerPowSubmodule_le_maximalIdealFieldSubmodule_of_fg
    [TopologicalSpace L] [IsNonarchimedeanLocalField L]
    {N : Submodule 𝒪[K] L} (hN : N.FG) :
    ∃ n : Nat,
      chosenBaseUniformizerPowSubmodule K L n N ≤ maximalIdealFieldSubmodule K L
CyclicCohomology.exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_le_maximalIdealFieldSubmodule

Some uniformizer-power normal-basis lattice lies inside the maximal-ideal field submodule.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem
  exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_le_maximalIdealFieldSubmodule
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] :
    ∃ n : Nat,
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
        maximalIdealFieldSubmodule K L
CyclicCohomology.exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_le_maximalIdeal_and_mul_closed

A sufficiently deep normal-basis lattice lies in the maximal ideal and is multiplicatively closed.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem
  exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_le_maximalIdeal_and_mul_closed
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
        maximalIdealFieldSubmodule K L ∧
      ∀ x : L,
        x ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
        ∀ y : L,
          y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
            x * y ∈
              chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.chosenNormalBasisPrincipalUnitSet

The actual carrier of the classical auxiliary principal-unit lattice V^n = 1 + π_K^n M, viewed as a set of units of 𝒪_L.

This set becomes a subgroup once inverse closure is supplied by the complete geometric-series argument.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisPrincipalUnitSet (n : Nat) : Set 𝒪[L]ˣ
CyclicCohomology.mem_chosenNormalBasisPrincipalUnitSet_iff

Characterizes membership in the principal-unit set arising from a normal-basis lattice.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem mem_chosenNormalBasisPrincipalUnitSet_iff (n : Nat) (u : 𝒪[L]ˣ) :
    u ∈ chosenNormalBasisPrincipalUnitSet K L n ↔
      ((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) ∈
        chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_one_mem

The identity belongs to the chosen normal-basis principal-unit set.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisPrincipalUnitSet_one_mem (n : Nat) :
    (1 : 𝒪[L]ˣ) ∈ chosenNormalBasisPrincipalUnitSet K L n
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_mul_mem

The chosen normal-basis principal-unit set is closed under multiplication.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisPrincipalUnitSet_mul_mem {n : Nat}
    (hmul : ∀ x : L,
      x ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
      ∀ y : L,
        y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
          x * y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L))
    {u v : 𝒪[L]ˣ}
    (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n)
    (hv : v ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    u * v ∈ chosenNormalBasisPrincipalUnitSet K L n
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_mem_principalUnits_one

Every chosen normal-basis principal unit belongs to the first principal-unit group.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSet_mem_principalUnits_one {n : Nat}
    (hle : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
      maximalIdealFieldSubmodule K L)
    {u : 𝒪[L]ˣ} (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    u ∈ principalUnits L 1
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSet_mul_closed_le_principalUnits_one

There is a multiplicatively closed normal-basis principal-unit set inside the first principal-unit group.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenNormalBasisPrincipalUnitSet_mul_closed_le_principalUnits_one
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      (∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
        ∀ v : 𝒪[L]ˣ, v ∈ chosenNormalBasisPrincipalUnitSet K L n →
          u * v ∈ chosenNormalBasisPrincipalUnitSet K L n) ∧
      ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
        u ∈ principalUnits L 1
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_inverseCorrectionPartialSum_mem

The inverse-correction partial sums remain in the lattice underlying the principal-unit set.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisPrincipalUnitSet_inverseCorrectionPartialSum_mem {n : Nat}
    (hmul : ∀ x : L,
      x ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
      ∀ y : L,
        y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
          x * y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L))
    {u : 𝒪[L]ˣ} (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n) (d : Nat) :
    inverseCorrectionPartialSum (L := L)
        ((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) d ∈
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSet_inverseCorrectionPartialSum_mem

A suitable normal-basis principal-unit set contains every inverse-correction partial sum.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem exists_chosenNormalBasisPrincipalUnitSet_inverseCorrectionPartialSum_mem :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n → ∀ d : Nat,
        inverseCorrectionPartialSum (L := L)
            ((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) d ∈
          chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_inverseCorrectionPartialProductError_mem

The inverse-correction product error remains in the chosen lattice.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisPrincipalUnitSet_inverseCorrectionPartialProductError_mem {n : Nat}
    (hmul : ∀ x : L,
      x ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
      ∀ y : L,
        y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
          x * y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L))
    {u : 𝒪[L]ˣ} (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n) (d : Nat) :
    (((u : 𝒪[L]ˣ) : 𝒪[L]) : L) *
        (1 + inverseCorrectionPartialSum (L := L)
          ((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) d) - 1 ∈
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSet_inverseCorrectionPartialProductError_mem

A suitable normal-basis principal-unit set contains every inverse-correction product error.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem exists_chosenNormalBasisPrincipalUnitSet_inverseCorrectionPartialProductError_mem :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n → ∀ d : Nat,
        (((u : 𝒪[L]ˣ) : 𝒪[L]) : L) *
            (1 + inverseCorrectionPartialSum (L := L)
              ((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) d) - 1 ∈
          chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_neg_sub_one_pow_succ_tendsto_zero

Successive powers of the negative deviation from one converge to zero.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSet_neg_sub_one_pow_succ_tendsto_zero
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] {n : Nat}
    (hle : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
      maximalIdealFieldSubmodule K L)
    {u : 𝒪[L]ˣ} (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    Tendsto
      (fun d : Nat => (-(((u : 𝒪[L]ˣ) : 𝒪[L]) - 1)) ^ (d + 1))
      atTop (nhds (0 : 𝒪[L])) := by
  have hu_one : u ∈ principalUnits L 1 :=
    chosenNormalBasisPrincipalUnitSet_mem_principalUnits_one
      (K := K) (L := L) hle hu
  have hpow :
      (((u : 𝒪[L]ˣ) : 𝒪[L]) - 1) ∈ (𝓂[L] ^ 1 : Ideal 𝒪[L]) :=
    (mem_principalUnits_iff L u 1).1 hu_one
  have hmax :
      (((u : 𝒪[L]ˣ) : 𝒪[L]) - 1) ∈ (𝓂[L] : Ideal 𝒪[L]) := by
    simpa [pow_one] using hpow
  exact tendsto_neg_pow_succ_of_mem_maximalIdeal L hmax
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSet_neg_sub_one_pow_succ_tendsto_zero

A suitable normal-basis principal-unit set has powers of the negative deviation converging to zero.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenNormalBasisPrincipalUnitSet_neg_sub_one_pow_succ_tendsto_zero
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
        Tendsto
          (fun d : Nat => (-(((u : 𝒪[L]ˣ) : 𝒪[L]) - 1)) ^ (d + 1))
          atTop (nhds (0 : 𝒪[L])) := by
  rcases
    exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_le_maximalIdealFieldSubmodule
      (K := K) (L := L) with
    ⟨c, hc⟩
  refine ⟨c, ?_⟩
  intro n hcn u hu
  have hle :
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
        maximalIdealFieldSubmodule K L :=
    (chosenBaseUniformizerPowSubmodule_antitone
      (K := K) (L := L) (m := c) (n := n)
      (chosenNormalBasisIntegerLattice K L) hcn).trans hc
  exact chosenNormalBasisPrincipalUnitSet_neg_sub_one_pow_succ_tendsto_zero
    (K := K) (L := L) hle hu
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_inverseCorrectionProduct_tendsto_one

The inverse-correction partial products converge to one.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSet_inverseCorrectionProduct_tendsto_one
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] {n : Nat}
    (hle : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
      maximalIdealFieldSubmodule K L)
    {u : 𝒪[L]ˣ} (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    Tendsto
      (fun d : Nat =>
        (((u : 𝒪[L]ˣ) : 𝒪[L]) : L) *
          (1 + inverseCorrectionPartialSum (L := L)
            ((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) d))
      atTop (nhds (1 : L)) := by
  let x𝒪 : 𝒪[L] := ((u : 𝒪[L]ˣ) : 𝒪[L]) - 1
  let x : L := (x𝒪 : L)
  have hres𝒪 :
      Tendsto (fun d : Nat => (-x𝒪) ^ (d + 1)) atTop (nhds (0 : 𝒪[L])) := by
    simpa [x𝒪] using
      chosenNormalBasisPrincipalUnitSet_neg_sub_one_pow_succ_tendsto_zero
        (K := K) (L := L) hle hu
  have hresL :
      Tendsto (fun d : Nat => ((((-x𝒪) ^ (d + 1) : 𝒪[L]) : L)))
        atTop (nhds (0 : L)) :=
    (continuous_subtype_val.tendsto (0 : 𝒪[L])).comp hres𝒪
  have htarget :
      Tendsto (fun d : Nat => (1 : L) - ((((-x𝒪) ^ (d + 1) : 𝒪[L]) : L)))
        atTop (nhds (1 : L)) := by
    simpa using (tendsto_const_nhds (x := (1 : L))).sub hresL
  refine htarget.congr' (Eventually.of_forall ?_)
  intro d
  have hgeom :
      (1 + x) * (1 + inverseCorrectionPartialSum (L := L) x d) =
        1 - (-x) ^ (d + 1) :=
    one_add_mul_one_add_inverseCorrectionPartialSum (L := L) x d
  have hu_eq : 1 + x = (((u : 𝒪[L]ˣ) : 𝒪[L]) : L) := by
    simp [x, x𝒪]
  simpa [x, x𝒪, hu_eq] using hgeom.symm
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_one_add_inverseCorrection_tendsto_inv

One plus the inverse correction converges to the multiplicative inverse.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSet_one_add_inverseCorrection_tendsto_inv
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] {n : Nat}
    (hle : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
      maximalIdealFieldSubmodule K L)
    {u : 𝒪[L]ˣ} (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    Tendsto
      (fun d : Nat =>
        1 + inverseCorrectionPartialSum (L := L)
          ((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) d)
      atTop (nhds ((((u⁻¹ : 𝒪[L]ˣ) : 𝒪[L]) : L))) := by
  have hprod :=
    chosenNormalBasisPrincipalUnitSet_inverseCorrectionProduct_tendsto_one
      (K := K) (L := L) hle hu
  have hmul :
      Tendsto
        (fun d : Nat =>
          (((u⁻¹ : 𝒪[L]ˣ) : 𝒪[L]) : L) *
            ((((u : 𝒪[L]ˣ) : 𝒪[L]) : L) *
              (1 + inverseCorrectionPartialSum (L := L)
                ((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) d)))
        atTop (nhds ((((u⁻¹ : 𝒪[L]ˣ) : 𝒪[L]) : L))) := by
    simpa using
      (tendsto_const_nhds (x := (((u⁻¹ : 𝒪[L]ˣ) : 𝒪[L]) : L))).mul hprod
  refine hmul.congr' (Eventually.of_forall ?_)
  intro d
  have huinv :
      ((((u⁻¹ : 𝒪[L]ˣ) : 𝒪[L]) : L)) *
          ((((u : 𝒪[L]ˣ) : 𝒪[L]) : L)) = 1 := by
    have huinvₒ :
        (((u⁻¹ : 𝒪[L]ˣ) : 𝒪[L]) * ((u : 𝒪[L]ˣ) : 𝒪[L])) = 1 :=
      Units.inv_mul u
    exact congrArg (algebraMap 𝒪[L] L) huinvₒ
  rw [← mul_assoc, huinv, one_mul]
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_inverseCorrection_tendsto_inv_sub_one

The inverse correction converges to the inverse minus one.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSet_inverseCorrection_tendsto_inv_sub_one
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] {n : Nat}
    (hle : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
      maximalIdealFieldSubmodule K L)
    {u : 𝒪[L]ˣ} (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    Tendsto
      (fun d : Nat =>
        inverseCorrectionPartialSum (L := L)
          ((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) d)
      atTop (nhds (((((u⁻¹ : 𝒪[L]ˣ) : 𝒪[L]) : L) - 1))) := by
  have h :=
    chosenNormalBasisPrincipalUnitSet_one_add_inverseCorrection_tendsto_inv
      (K := K) (L := L) hle hu
  simpa [sub_eq_add_neg, add_assoc, add_comm, add_left_comm] using
    h.sub (tendsto_const_nhds (x := (1 : L)))
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSet_inverseCorrection_tendsto_inv_sub_one

A suitable normal-basis principal-unit set admits inverse corrections converging to the inverse minus one.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenNormalBasisPrincipalUnitSet_inverseCorrection_tendsto_inv_sub_one
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
        Tendsto
          (fun d : Nat =>
            inverseCorrectionPartialSum (L := L)
              ((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) d)
          atTop (nhds (((((u⁻¹ : 𝒪[L]ˣ) : 𝒪[L]) : L) - 1))) := by
  rcases
    exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_le_maximalIdealFieldSubmodule
      (K := K) (L := L) with
    ⟨c, hc⟩
  refine ⟨c, ?_⟩
  intro n hcn u hu
  have hle :
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
        maximalIdealFieldSubmodule K L :=
    (chosenBaseUniformizerPowSubmodule_antitone
      (K := K) (L := L) (m := c) (n := n)
      (chosenNormalBasisIntegerLattice K L) hcn).trans hc
  exact chosenNormalBasisPrincipalUnitSet_inverseCorrection_tendsto_inv_sub_one
    (K := K) (L := L) hle hu
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_inverse_sub_one_mem_of_closed

Closedness of the lattice puts the inverse minus one back in the lattice.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSet_inverse_sub_one_mem_of_closed
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] {n : Nat}
    (hclosed : IsClosed
      ((chosenBaseUniformizerPowSubmodule K L n
        (chosenNormalBasisIntegerLattice K L) : Set L)))
    (hle : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
      maximalIdealFieldSubmodule K L)
    (hmul : ∀ x : L,
      x ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
      ∀ y : L,
        y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
          x * y ∈ chosenBaseUniformizerPowSubmodule K L n
            (chosenNormalBasisIntegerLattice K L))
    {u : 𝒪[L]ˣ} (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    ((((u⁻¹ : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) ∈
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_inv_mem_of_closed

A closed normal-basis principal-unit set is closed under inversion.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSet_inv_mem_of_closed
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] {n : Nat}
    (hclosed : IsClosed
      ((chosenBaseUniformizerPowSubmodule K L n
        (chosenNormalBasisIntegerLattice K L) : Set L)))
    (hle : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) ≤
      maximalIdealFieldSubmodule K L)
    (hmul : ∀ x : L,
      x ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
      ∀ y : L,
        y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
          x * y ∈ chosenBaseUniformizerPowSubmodule K L n
            (chosenNormalBasisIntegerLattice K L))
    {u : 𝒪[L]ˣ} (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    u⁻¹ ∈ chosenNormalBasisPrincipalUnitSet K L n
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSet_inv_mem_of_closed

There is a closed normal-basis principal-unit set stable under inversion.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenNormalBasisPrincipalUnitSet_inv_mem_of_closed
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      IsClosed
        ((chosenBaseUniformizerPowSubmodule K L n
          (chosenNormalBasisIntegerLattice K L) : Set L)) →
      ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
        u⁻¹ ∈ chosenNormalBasisPrincipalUnitSet K L n
CyclicCohomology.integerRingToFieldLinearMap_range_eq

The range of the integer-ring inclusion is the integer-ring field submodule.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] [TopologicalSpace K]
  [IsNonarchimedeanLocalField K] in
theorem integerRingToFieldLinearMap_range_eq :
    LinearMap.range (integerRingToFieldLinearMap K L) =
      integerRingFieldSubmodule K L
CyclicCohomology.integerRingFieldSubmodule_fg_of_moduleFinite

If the extension valuation ring is finite over the base valuation ring, then 𝒪_L, viewed inside L, is a finitely generated 𝒪_K-submodule.

Source context 11 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [FiniteDimensional K L] [IsGalois K L] [TopologicalSpace K]
  [IsNonarchimedeanLocalField K] in
theorem integerRingFieldSubmodule_fg_of_moduleFinite
    [Module.Finite 𝒪[K] 𝒪[L]] :
    (integerRingFieldSubmodule K L).FG
CyclicCohomology.exists_chosenBaseUniformizerPow_integerRingFieldSubmodule_le_chosenNormalBasisIntegerLattice

The reverse lattice bound: if 𝒪_L is finite over 𝒪_K, then a single high enough base-uniformizer power sends 𝒪_L into the normal-basis lattice M.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenBaseUniformizerPow_integerRingFieldSubmodule_le_chosenNormalBasisIntegerLattice
    [Module.Finite 𝒪[K] 𝒪[L]] :
    ∃ n : Nat,
      chosenBaseUniformizerPowSubmodule K L n (integerRingFieldSubmodule K L) ≤
        chosenNormalBasisIntegerLattice K L
CyclicCohomology.exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_mem_nhds_zero

Some uniformizer-power normal-basis lattice is a neighborhood of zero.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_mem_nhds_zero
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] [Module.Finite 𝒪[K] 𝒪[L]] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      ((chosenBaseUniformizerPowSubmodule K L n
        (chosenNormalBasisIntegerLattice K L) : Set L)) ∈ nhds (0 : L)
CyclicCohomology.exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_isClosed

Some uniformizer-power normal-basis lattice is closed.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenBaseUniformizerPow_chosenNormalBasisIntegerLattice_isClosed
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] [Module.Finite 𝒪[K] 𝒪[L]] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      IsClosed
        ((chosenBaseUniformizerPowSubmodule K L n
          (chosenNormalBasisIntegerLattice K L) : Set L))
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSet_inv_mem

There is a chosen normal-basis principal-unit set stable under inversion.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenNormalBasisPrincipalUnitSet_inv_mem
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] [Module.Finite 𝒪[K] 𝒪[L]] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
        u⁻¹ ∈ chosenNormalBasisPrincipalUnitSet K L n
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSubgroup

There exists a principal-unit subgroup arising from a chosen normal-basis lattice.

Source context 10 commands

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

namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
universe u
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L]
variable [ValuativeRel K]
variable [TopologicalSpace K] [IsNonarchimedeanLocalField K]
variable [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenNormalBasisPrincipalUnitSubgroup
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] [Module.Finite 𝒪[K] 𝒪[L]] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      ∃ V : Subgroup 𝒪[L]ˣ,
        (V : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L n ∧
        V ≤ principalUnits L 1
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_succ_subset

The principal-unit lattice carriers form a descending filtration.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisPrincipalUnitSet_succ_subset (n : Nat) :
    chosenNormalBasisPrincipalUnitSet K L (n + 1) ⊆
      chosenNormalBasisPrincipalUnitSet K L n
CyclicCohomology.chosenNormalBasisLatticeSuccSubmodule

The denominator submodule π_K^(n+1)M, viewed inside π_K^nM.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisLatticeSuccSubmodule (n : Nat) :
    Submodule 𝒪[K]
      (chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L))
CyclicCohomology.chosenNormalBasisLatticeSuccQuot

The additive quotient π_K^nM / π_K^(n+1)M used in the local class-field calculation.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisLatticeSuccQuot (n : Nat) : Type u
CyclicCohomology.chosenNormalBasisLatticeSuccQuotAddCommGroup

A successive quotient of normal-basis lattices is an additive commutative group.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
instance chosenNormalBasisLatticeSuccQuotAddCommGroup (n : Nat) :
    AddCommGroup (chosenNormalBasisLatticeSuccQuot K L n)
CyclicCohomology.chosenNormalBasisLatticeSuccQuotModule

A successive normal-basis lattice quotient carries the natural residue-field module structure.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
instance chosenNormalBasisLatticeSuccQuotModule (n : Nat) :
    Module 𝒪[K] (chosenNormalBasisLatticeSuccQuot K L n)
CyclicCohomology.chosenNormalBasisLatticeSuccQuotConcreteLinearEquiv

Explicit access to the concrete submodule quotient implementing the chosen normal-basis lattice graded piece.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisLatticeSuccQuotConcreteLinearEquiv (n : Nat) :
    chosenNormalBasisLatticeSuccQuot K L n ≃ₗ[𝒪[K]]
      ((chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)) ⧸
        chosenNormalBasisLatticeSuccSubmodule K L n)
CyclicCohomology.mem_chosenNormalBasisLatticeSuccSubmodule_iff

Characterizes membership in the next normal-basis lattice submodule.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem mem_chosenNormalBasisLatticeSuccSubmodule_iff (n : Nat)
    (x : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)) :
    x ∈ chosenNormalBasisLatticeSuccSubmodule K L n ↔
      (x : L) ∈ chosenBaseUniformizerPowSubmodule K L (n + 1)
        (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.chosenNormalBasisLatticeSuccQuotMk

The quotient map π_K^nM -> π_K^nM / π_K^(n+1)M.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisLatticeSuccQuotMk (n : Nat) :
    chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →ₗ[𝒪[K]]
      chosenNormalBasisLatticeSuccQuot K L n
CyclicCohomology.chosenNormalBasisLatticeSuccQuotConcreteLinearEquiv_mk

The concrete linear equivalence sends a lattice element to its canonical quotient class.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisLatticeSuccQuotConcreteLinearEquiv_mk (n : Nat)
    (x : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)) :
    chosenNormalBasisLatticeSuccQuotConcreteLinearEquiv K L n
        (chosenNormalBasisLatticeSuccQuotMk K L n x) =
      Submodule.Quotient.mk x
CyclicCohomology.chosenNormalBasisLatticeSuccQuotMk_surjective

Every successive lattice-quotient class has a representative.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisLatticeSuccQuotMk_surjective (n : Nat) :
    Function.Surjective (chosenNormalBasisLatticeSuccQuotMk K L n)
CyclicCohomology.chosenNormalBasisLatticeSuccQuot.inductionOn

Eliminate a chosen normal-basis lattice quotient through arbitrary representatives and its canonical class map.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisLatticeSuccQuot.inductionOn
    (n : Nat)
    {motive : chosenNormalBasisLatticeSuccQuot K L n → Prop}
    (q : chosenNormalBasisLatticeSuccQuot K L n)
    (h : ∀ x :
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L),
      motive (chosenNormalBasisLatticeSuccQuotMk K L n x)) :
    motive q
CyclicCohomology.chosenNormalBasisLatticeSuccQuotLift

Descend a representative-level function constant modulo the next chosen normal-basis lattice.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisLatticeSuccQuotLift
    {P : Sort*} (n : Nat)
    (f :
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) → P)
    (h : ∀ x y, x - y ∈ chosenNormalBasisLatticeSuccSubmodule K L n →
      f x = f y) :
    chosenNormalBasisLatticeSuccQuot K L n → P
CyclicCohomology.chosenNormalBasisLatticeSuccQuotLift_mk

The lifted map on a successive lattice quotient evaluates to the original map on representatives.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisLatticeSuccQuotLift_mk
    {P : Sort*} (n : Nat)
    (f :
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) → P)
    (h : ∀ x y, x - y ∈ chosenNormalBasisLatticeSuccSubmodule K L n →
      f x = f y)
    (x : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)) :
    chosenNormalBasisLatticeSuccQuotLift K L n f h
        (chosenNormalBasisLatticeSuccQuotMk K L n x) = f x
CyclicCohomology.chosenNormalBasisLatticeSuccQuotLinearLift

Descend a linear map vanishing on the next chosen normal-basis lattice.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisLatticeSuccQuotLinearLift
    {M : Type*} [AddCommGroup M] [Module 𝒪[K] M] (n : Nat)
    (f :
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)
        →ₗ[𝒪[K]] M)
    (h : chosenNormalBasisLatticeSuccSubmodule K L n ≤ f.ker) :
    chosenNormalBasisLatticeSuccQuot K L n →ₗ[𝒪[K]] M
CyclicCohomology.chosenNormalBasisLatticeSuccQuotLinearLift_mk

The lifted linear map agrees with the original linear map on quotient representatives.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisLatticeSuccQuotLinearLift_mk
    {M : Type*} [AddCommGroup M] [Module 𝒪[K] M] (n : Nat)
    (f :
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)
        →ₗ[𝒪[K]] M)
    (h : chosenNormalBasisLatticeSuccSubmodule K L n ≤ f.ker)
    (x : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)) :
    chosenNormalBasisLatticeSuccQuotLinearLift K L n f h
        (chosenNormalBasisLatticeSuccQuotMk K L n x) = f x
CyclicCohomology.chosenNormalBasisLatticeSuccQuotMk_eq_zero_iff

A lattice representative gives zero in the successive quotient exactly when it lies at the next level.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisLatticeSuccQuotMk_eq_zero_iff (n : Nat)
    (x : chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)) :
    chosenNormalBasisLatticeSuccQuotMk K L n x = 0 ↔
      (x : L) ∈ chosenBaseUniformizerPowSubmodule K L (n + 1)
        (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.chosenNormalBasisLatticeSuccQuotMk_eq_iff

Two lattice representatives agree in the successive quotient exactly when their difference lies at the next level.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisLatticeSuccQuotMk_eq_iff (n : Nat)
    (x y :
      chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L)) :
    chosenNormalBasisLatticeSuccQuotMk K L n x =
        chosenNormalBasisLatticeSuccQuotMk K L n y ↔
      x - y ∈ chosenNormalBasisLatticeSuccSubmodule K L n
CyclicCohomology.chosenNormalBasisPrincipalUnitLatticeClass

The additive quotient class of u - 1 for u ∈ V^n.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisPrincipalUnitLatticeClass (n : Nat)
    (u : 𝒪[L]ˣ) (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    chosenNormalBasisLatticeSuccQuot K L n
CyclicCohomology.chosenNormalBasisPrincipalUnitLatticeClass_eq_zero_iff

A principal unit has zero lattice class exactly when its deviation from one lies at the next level.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisPrincipalUnitLatticeClass_eq_zero_iff {n : Nat}
    (u : 𝒪[L]ˣ) (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    chosenNormalBasisPrincipalUnitLatticeClass K L n u hu = 0 ↔
      u ∈ chosenNormalBasisPrincipalUnitSet K L (n + 1)
CyclicCohomology.chosenNormalBasisPrincipalUnitSet_mul_error_mem_succ

The multiplicative error term for units in V^n is one lattice step deeper whenever products of elements of π_K^nM land in π_K^(n+1)M.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisPrincipalUnitSet_mul_error_mem_succ {n : Nat}
    (hmul_succ : ∀ x : L,
      x ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
      ∀ y : L,
        y ∈ chosenBaseUniformizerPowSubmodule K L n (chosenNormalBasisIntegerLattice K L) →
          x * y ∈
            chosenBaseUniformizerPowSubmodule K L (n + 1) (chosenNormalBasisIntegerLattice K L))
    {u v : 𝒪[L]ˣ}
    (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n)
    (hv : v ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    (((((u * v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) -
        (((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) +
          ((((v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L))) ∈
      chosenBaseUniformizerPowSubmodule K L (n + 1)
        (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSet_mul_error_mem_succ

A suitable normal-basis principal-unit set has multiplication error in the next lattice level.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem exists_chosenNormalBasisPrincipalUnitSet_mul_error_mem_succ :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
        ∀ v : 𝒪[L]ˣ, v ∈ chosenNormalBasisPrincipalUnitSet K L n →
          (((((u * v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) -
              (((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) +
                ((((v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L))) ∈
            chosenBaseUniformizerPowSubmodule K L (n + 1)
              (chosenNormalBasisIntegerLattice K L)
CyclicCohomology.chosenNormalBasisPrincipalUnitLatticeClass_mul_eq_add

The lattice class of a product of principal units is the sum of their lattice classes.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisPrincipalUnitLatticeClass_mul_eq_add {n : Nat}
    (hmul_error : ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
      ∀ v : 𝒪[L]ˣ, v ∈ chosenNormalBasisPrincipalUnitSet K L n →
        (((((u * v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) -
            (((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) +
              ((((v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L))) ∈
          chosenBaseUniformizerPowSubmodule K L (n + 1)
            (chosenNormalBasisIntegerLattice K L))
    (u v : 𝒪[L]ˣ)
    (hu : u ∈ chosenNormalBasisPrincipalUnitSet K L n)
    (hv : v ∈ chosenNormalBasisPrincipalUnitSet K L n)
    (huv : u * v ∈ chosenNormalBasisPrincipalUnitSet K L n) :
    chosenNormalBasisPrincipalUnitLatticeClass K L n (u * v) huv =
      chosenNormalBasisPrincipalUnitLatticeClass K L n u hu +
        chosenNormalBasisPrincipalUnitLatticeClass K L n v hv
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSubgroupSuccPair

There exists a nested pair of normal-basis principal-unit subgroups at successive levels.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenNormalBasisPrincipalUnitSubgroupSuccPair
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] [Module.Finite 𝒪[K] 𝒪[L]] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      ∃ Vn Vsucc : Subgroup 𝒪[L]ˣ,
        (Vn : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L n ∧
        (Vsucc : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L (n + 1) ∧
        Vsucc ≤ Vn ∧
        Vn ≤ principalUnits L 1
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccSubgroup

The subgroup of Vn obtained from an included next-step subgroup Vsucc ≤ Vn. This is the denominator used for the multiplicative quotient V^n / V^(n+1).

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisPrincipalUnitSuccSubgroup {Vn Vsucc : Subgroup 𝒪[L]ˣ}
    (_hV : Vsucc ≤ Vn) : Subgroup Vn
CyclicCohomology.mem_chosenNormalBasisPrincipalUnitSuccSubgroup_iff

Characterizes membership in the next normal-basis principal-unit subgroup.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem mem_chosenNormalBasisPrincipalUnitSuccSubgroup_iff
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} (hV : Vsucc ≤ Vn) (u : Vn) :
    u ∈ chosenNormalBasisPrincipalUnitSuccSubgroup (L := L) hV ↔
      (u : 𝒪[L]ˣ) ∈ Vsucc
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuot

The multiplicative successive quotient Vn / Vsucc, for an actual inclusion Vsucc ≤ Vn.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisPrincipalUnitSuccQuot
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} (hV : Vsucc ≤ Vn) : Type u
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuotCommGroup

The quotient by the next normal-basis principal-unit subgroup is a commutative group.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
instance chosenNormalBasisPrincipalUnitSuccQuotCommGroup
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} (hV : Vsucc ≤ Vn) :
    CommGroup (chosenNormalBasisPrincipalUnitSuccQuot (L := L) hV)
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuotConcreteEquiv

Explicit access to the concrete group quotient implementing the chosen normal-basis principal-unit graded piece.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisPrincipalUnitSuccQuotConcreteEquiv
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} (hV : Vsucc ≤ Vn) :
    chosenNormalBasisPrincipalUnitSuccQuot (L := L) hV ≃*
      (Vn ⧸ chosenNormalBasisPrincipalUnitSuccSubgroup (L := L) hV)
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuotMk

The quotient map Vn -> Vn / Vsucc.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisPrincipalUnitSuccQuotMk
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} (hV : Vsucc ≤ Vn) :
    Vn →* chosenNormalBasisPrincipalUnitSuccQuot (L := L) hV
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuotConcreteEquiv_mk

The concrete principal-unit quotient equivalence sends an element to its canonical class.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSuccQuotConcreteEquiv_mk
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} (hV : Vsucc ≤ Vn) (u : Vn) :
    chosenNormalBasisPrincipalUnitSuccQuotConcreteEquiv (L := L) hV
        (chosenNormalBasisPrincipalUnitSuccQuotMk (L := L) hV u) =
      QuotientGroup.mk u
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuotMk_surjective

Every successive principal-unit quotient class has a representative.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSuccQuotMk_surjective
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} (hV : Vsucc ≤ Vn) :
    Function.Surjective
      (chosenNormalBasisPrincipalUnitSuccQuotMk (L := L) hV)
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuot.inductionOn

Eliminate a chosen normal-basis principal-unit quotient through arbitrary representatives and its canonical class map.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSuccQuot.inductionOn
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} (hV : Vsucc ≤ Vn)
    {motive : chosenNormalBasisPrincipalUnitSuccQuot (L := L) hV → Prop}
    (q : chosenNormalBasisPrincipalUnitSuccQuot (L := L) hV)
    (h : ∀ u : Vn,
      motive (chosenNormalBasisPrincipalUnitSuccQuotMk (L := L) hV u)) :
    motive q
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuotLift

Descend a homomorphism that kills the included next-step subgroup.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisPrincipalUnitSuccQuotLift
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} {H : Type*} [Group H]
    (hV : Vsucc ≤ Vn) (f : Vn →* H)
    (h : chosenNormalBasisPrincipalUnitSuccSubgroup (L := L) hV ≤ f.ker) :
    chosenNormalBasisPrincipalUnitSuccQuot (L := L) hV →* H
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuotLift_mk

A map lifted from the successive principal-unit quotient agrees on representatives.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSuccQuotLift_mk
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} {H : Type*} [Group H]
    (hV : Vsucc ≤ Vn) (f : Vn →* H)
    (h : chosenNormalBasisPrincipalUnitSuccSubgroup (L := L) hV ≤ f.ker)
    (u : Vn) :
    chosenNormalBasisPrincipalUnitSuccQuotLift (L := L) hV f h
        (chosenNormalBasisPrincipalUnitSuccQuotMk (L := L) hV u) = f u
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuotMk_eq_one_iff

A principal unit represents the identity exactly when it lies in the next subgroup.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSuccQuotMk_eq_one_iff
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} (hV : Vsucc ≤ Vn) (u : Vn) :
    chosenNormalBasisPrincipalUnitSuccQuotMk (L := L) hV u = 1 ↔
      (u : 𝒪[L]ˣ) ∈ Vsucc
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuotMk_eq_iff_div_mem

Two principal units represent the same class exactly when their quotient lies in the next subgroup.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem chosenNormalBasisPrincipalUnitSuccQuotMk_eq_iff_div_mem
    {Vn Vsucc : Subgroup 𝒪[L]ˣ} (hV : Vsucc ≤ Vn) (u v : Vn) :
    chosenNormalBasisPrincipalUnitSuccQuotMk (L := L) hV u =
        chosenNormalBasisPrincipalUnitSuccQuotMk (L := L) hV v ↔
      u / v ∈ chosenNormalBasisPrincipalUnitSuccSubgroup (L := L) hV
CyclicCohomology.chosenNormalBasisPrincipalUnitToLatticeSuccQuotHom

The map u ↦ u - 1 from a subgroup Vn = V^n to the additive successive quotient, viewed multiplicatively on the target.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisPrincipalUnitToLatticeSuccQuotHom (n : Nat)
    {Vn : Subgroup 𝒪[L]ˣ}
    (hVn : (Vn : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L n)
    (hmul_error : ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
      ∀ v : 𝒪[L]ˣ, v ∈ chosenNormalBasisPrincipalUnitSet K L n →
        (((((u * v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) -
            (((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) +
              ((((v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L))) ∈
          chosenBaseUniformizerPowSubmodule K L (n + 1)
            (chosenNormalBasisIntegerLattice K L)) :
    Vn →* Multiplicative (chosenNormalBasisLatticeSuccQuot K L n) where
  toFun u :=
    Multiplicative.ofAdd
      (chosenNormalBasisPrincipalUnitLatticeClass K L n (u : 𝒪[L]ˣ)
        (by
          exact hVn ▸ u.2))
  map_one' := by
    change chosenNormalBasisPrincipalUnitLatticeClass K L n
      (1 : 𝒪[L]ˣ) (by exact hVn ▸ (1 : Vn).2) = 0
    rw [chosenNormalBasisPrincipalUnitLatticeClass,
      chosenNormalBasisLatticeSuccQuotMk_eq_zero_iff]
    simp
  map_mul' := by
    intro u v
    have hu : (u : 𝒪[L]ˣ) ∈ chosenNormalBasisPrincipalUnitSet K L n := by
      exact hVn ▸ u.2
    have hv : (v : 𝒪[L]ˣ) ∈ chosenNormalBasisPrincipalUnitSet K L n := by
      exact hVn ▸ v.2
    have huv : ((u * v : Vn) : 𝒪[L]ˣ) ∈ chosenNormalBasisPrincipalUnitSet K L n := by
      exact hVn ▸ (u * v).2
    have hclass :=
      chosenNormalBasisPrincipalUnitLatticeClass_mul_eq_add
        (K := K) (L := L) hmul_error (u : 𝒪[L]ˣ) (v : 𝒪[L]ˣ) hu hv huv
    simpa using congrArg Multiplicative.ofAdd hclass
CyclicCohomology.chosenNormalBasisPrincipalUnitToLatticeSuccQuotHom_mem_ker_of_mem_succ

Principal units from the next level lie in the kernel of the lattice-class homomorphism.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisPrincipalUnitToLatticeSuccQuotHom_mem_ker_of_mem_succ
    {n : Nat} {Vn Vsucc : Subgroup 𝒪[L]ˣ}
    (hVn : (Vn : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L n)
    (hVsucc : (Vsucc : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L (n + 1))
    (hmul_error : ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
      ∀ v : 𝒪[L]ˣ, v ∈ chosenNormalBasisPrincipalUnitSet K L n →
        (((((u * v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) -
            (((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) +
              ((((v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L))) ∈
          chosenBaseUniformizerPowSubmodule K L (n + 1)
            (chosenNormalBasisIntegerLattice K L))
    (u : Vn) (hu : (u : 𝒪[L]ˣ) ∈ Vsucc) :
    u ∈ (chosenNormalBasisPrincipalUnitToLatticeSuccQuotHom
      K L n hVn hmul_error).ker
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuotToLatticeSuccQuotHom

The induced map Vn/Vsucc -> π_K^nM/π_K^(n+1)M, with the additive quotient target viewed as a multiplicative group.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
def chosenNormalBasisPrincipalUnitSuccQuotToLatticeSuccQuotHom (n : Nat)
    {Vn Vsucc : Subgroup 𝒪[L]ˣ}
    (hVn : (Vn : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L n)
    (hVsucc : (Vsucc : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L (n + 1))
    (hV : Vsucc ≤ Vn)
    (hmul_error : ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
      ∀ v : 𝒪[L]ˣ, v ∈ chosenNormalBasisPrincipalUnitSet K L n →
        (((((u * v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) -
            (((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) +
              ((((v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L))) ∈
          chosenBaseUniformizerPowSubmodule K L (n + 1)
            (chosenNormalBasisIntegerLattice K L)) :
    chosenNormalBasisPrincipalUnitSuccQuot (L := L) hV →*
      Multiplicative (chosenNormalBasisLatticeSuccQuot K L n)
CyclicCohomology.chosenNormalBasisPrincipalUnitSuccQuotToLatticeSuccQuotHom_mk

The induced quotient homomorphism sends a principal-unit class to its lattice class.

Source context 8 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
omit [Valuation.HasExtension
  (ValuativeRel.valuation K) (ValuativeRel.valuation L)] in
theorem chosenNormalBasisPrincipalUnitSuccQuotToLatticeSuccQuotHom_mk
    {n : Nat} {Vn Vsucc : Subgroup 𝒪[L]ˣ}
    (hVn : (Vn : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L n)
    (hVsucc : (Vsucc : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L (n + 1))
    (hV : Vsucc ≤ Vn)
    (hmul_error : ∀ u : 𝒪[L]ˣ, u ∈ chosenNormalBasisPrincipalUnitSet K L n →
      ∀ v : 𝒪[L]ˣ, v ∈ chosenNormalBasisPrincipalUnitSet K L n →
        (((((u * v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) -
            (((((u : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L) +
              ((((v : 𝒪[L]ˣ) : 𝒪[L]) - 1 : 𝒪[L]) : L))) ∈
          chosenBaseUniformizerPowSubmodule K L (n + 1)
            (chosenNormalBasisIntegerLattice K L))
    (u : Vn) :
    chosenNormalBasisPrincipalUnitSuccQuotToLatticeSuccQuotHom
        K L n hVn hVsucc hV hmul_error
        (chosenNormalBasisPrincipalUnitSuccQuotMk (L := L) hV u) =
      chosenNormalBasisPrincipalUnitToLatticeSuccQuotHom K L n hVn hmul_error u
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSuccQuotBoundary

There exists a boundary map for the successive normal-basis principal-unit quotient.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenNormalBasisPrincipalUnitSuccQuotBoundary
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] [Module.Finite 𝒪[K] 𝒪[L]] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      ∃ Vn Vsucc : Subgroup 𝒪[L]ˣ,
        ∃ hV : Vsucc ≤ Vn,
          (Vn : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L n ∧
          (Vsucc : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L (n + 1) ∧
          Vn ≤ principalUnits L 1 ∧
          ∀ u : Vn,
            chosenNormalBasisPrincipalUnitSuccQuotMk (L := L) hV u = 1 ↔
              (u : 𝒪[L]ˣ) ∈ Vsucc
CyclicCohomology.exists_chosenNormalBasisPrincipalUnitSuccQuotToLatticeSuccQuotHom

There exists a homomorphism from the successive principal-unit quotient to the lattice quotient.

Source context 7 commands

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

universe u
namespace CyclicCohomology
open LocalFieldTheory
noncomputable section
open scoped ValuativeRel
open Filter
variable (K L : Type u) [Field K] [Field L] [Algebra K L]
  [FiniteDimensional K L] [IsGalois K L] [ValuativeRel K]
  [TopologicalSpace K] [IsNonarchimedeanLocalField K] [ValuativeRel L]
  [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
theorem exists_chosenNormalBasisPrincipalUnitSuccQuotToLatticeSuccQuotHom
    [TopologicalSpace L] [IsNonarchimedeanLocalField L] [Module.Finite 𝒪[K] 𝒪[L]] :
    ∃ c : Nat, ∀ n : Nat, c ≤ n →
      ∃ Vn Vsucc : Subgroup 𝒪[L]ˣ,
        ∃ hV : Vsucc ≤ Vn,
          ∃ hVn : (Vn : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L n,
            ∃ _hVsucc :
              (Vsucc : Set 𝒪[L]ˣ) = chosenNormalBasisPrincipalUnitSet K L (n + 1),
              ∃ Φ : chosenNormalBasisPrincipalUnitSuccQuot (L := L) hV →*
                  Multiplicative (chosenNormalBasisLatticeSuccQuot K L n),
                ∀ u : Vn,
                  Φ (chosenNormalBasisPrincipalUnitSuccQuotMk (L := L) hV u) =
                    Multiplicative.ofAdd
                      (chosenNormalBasisPrincipalUnitLatticeClass K L n
                        (u : 𝒪[L]ˣ) (by
                          exact hVn ▸ u.2)) := by
  rcases exists_chosenNormalBasisPrincipalUnitSubgroupSuccPair (K := K) (L := L) with
    ⟨c₁, hc₁⟩
  rcases exists_chosenNormalBasisPrincipalUnitSet_mul_error_mem_succ (K := K) (L := L) with
    ⟨c₂, hc₂⟩
  refine ⟨max c₁ c₂, ?_⟩
  intro n hmaxn
  have hc₁n : c₁ ≤ n := le_trans (le_max_left c₁ c₂) hmaxn
  have hc₂n : c₂ ≤ n := le_trans (le_max_right c₁ c₂) hmaxn
  rcases hc₁ n hc₁n with ⟨Vn, Vsucc, hVn, hVsucc, hV, _hVnle⟩
  let hmul_error := hc₂ n hc₂n
  let Φ : chosenNormalBasisPrincipalUnitSuccQuot (L := L) hV →*
      Multiplicative (chosenNormalBasisLatticeSuccQuot K L n) :=
    chosenNormalBasisPrincipalUnitSuccQuotToLatticeSuccQuotHom
      K L n hVn hVsucc hV hmul_error
  refine ⟨Vn, Vsucc, hV, hVn, hVsucc, Φ, ?_⟩
  intro u
  dsimp [Φ]
  rw [chosenNormalBasisPrincipalUnitSuccQuotToLatticeSuccQuotHom_mk]
  rfl