Module

HerbrandFormula.lean

Nyll.ClassFieldTheory.LubinTate.FiniteLevel.HerbrandFormula
16 declarations indexed from sourceView source ↗

Herbrand formula for finite Lubin--Tate levels

The explicit lower ramification groups determine the slopes of the Herbrand function. Summing those slopes sends the lower breaks q ^ k - 1 to the integral upper breaks k. Consequently the upper ramification group at k is the Galois image of the k-th principal-unit subgroup and has order q ^ (n + 1 - k).

Declarations

LubinTate.standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
Source context 8 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n)
LubinTate.standardLubinTateLevelField_isGalois_forHerbrandFormula
Source context 9 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n)
LubinTate.standardLubinTateUnitParameterSubgroup_zero_eq_top
Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem standardLubinTateUnitParameterSubgroup_zero_eq_top
    (F : LocalField.{u, v} K) (n : ℕ) :
    standardLubinTateUnitParameterSubgroup F n 0 = ⊤
LubinTate.standardLubinTateRealLowerRamificationGroup_zero_eq_top
Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem standardLubinTateRealLowerRamificationGroup_zero_eq_top
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n : ℕ) :
    standardLubinTateRealLowerRamificationGroup hπ n 0 = ⊤
LubinTate.standardLubinTateRealLowerRamificationGroup_zero_natCard
Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem standardLubinTateRealLowerRamificationGroup_zero_natCard
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n : ℕ) :
    Nat.card (standardLubinTateRealLowerRamificationGroup hπ n 0) =
      (Nat.card F.residueField - 1) *
        Nat.card F.residueField ^ n
LubinTate.standardLubinTateHerbrandSlope_eq_of_pow_interval

On a lower-numbering power interval, the Herbrand slope is the ratio of the corresponding lower-group order to the inertia-group order.

Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem standardLubinTateHerbrandSlope_eq_of_pow_interval
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n k i : ℕ) (hk : 1 ≤ k) (hkn : k ≤ n + 1)
    (hlow : Nat.card F.residueField ^ (k - 1) ≤ i + 1)
    (hhigh : i + 1 < Nat.card F.residueField ^ k) :
    AntitoneNormalSubgroupFiltration.herbrandSlope
        (standardLubinTateLowerRamificationFiltration hπ n) i =
      (Nat.card F.residueField ^ (n + 1 - k) : ℕ) /
        ((Nat.card F.residueField - 1) *
          Nat.card F.residueField ^ n : ℕ)
LubinTate.standardLubinTateHerbrandValueNat_pow_sub_one
Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem standardLubinTateHerbrandValueNat_pow_sub_one
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n k : ℕ) (hkn : k ≤ n + 1) :
    AntitoneNormalSubgroupFiltration.herbrandValueNat
        (standardLubinTateLowerRamificationFiltration hπ n)
        (Nat.card F.residueField ^ k - 1) =
      (k : ℝ)
LubinTate.standardLubinTateHerbrandFunction_pow_sub_one

The lower endpoints q ^ k - 1 map to the integral upper endpoints k, including the endpoint k = 0.

Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem standardLubinTateHerbrandFunction_pow_sub_one
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n k : ℕ) (hkn : k ≤ n + 1) :
    standardLubinTateHerbrandFunction hπ n
        ((Nat.card F.residueField ^ k - 1 : ℕ) : ℝ) =
      (k : ℝ)
LubinTate.standardLubinTateInverseHerbrandFunction_nat_eq_pow_sub_one

At an integral upper endpoint, the inverse Herbrand function returns the lower endpoint q ^ k - 1.

Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem standardLubinTateInverseHerbrandFunction_nat_eq_pow_sub_one
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n k : ℕ) (hkn : k ≤ n + 1) :
    standardLubinTateInverseHerbrandFunction hπ n (k : ℝ) =
      ((Nat.card F.residueField ^ k - 1 : ℕ) : ℝ)
LubinTate.standardLubinTateRealUpperRamificationGroup_nat_eq_lower_pow_sub_one

At an integral upper index, the upper group is the lower group at the corresponding power break.

Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem
    standardLubinTateRealUpperRamificationGroup_nat_eq_lower_pow_sub_one
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n k : ℕ) (hkn : k ≤ n + 1) :
    standardLubinTateRealUpperRamificationGroup hπ n (k : ℝ) =
      standardLubinTateRealLowerRamificationGroup hπ n
        ((Nat.card F.residueField ^ k - 1 : ℕ) : ℝ)
LubinTate.standardLubinTateRealUpperRamificationGroup_nat_eq_galoisParameterSubgroup

For 1 ≤ k ≤ n + 1, the integral upper group is the Galois image of the k-th finite principal-unit subgroup.

Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem
    standardLubinTateRealUpperRamificationGroup_nat_eq_galoisParameterSubgroup
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n k : ℕ) (hk : 1 ≤ k) (hkn : k ≤ n + 1) :
    standardLubinTateRealUpperRamificationGroup hπ n (k : ℝ) =
      standardLubinTateGaloisParameterSubgroup F hπ n k
LubinTate.standardLubinTateRealUpperRamificationGroup_natCard

For 1 ≤ k ≤ n + 1, the integral upper group has order q ^ (n + 1 - k).

Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem standardLubinTateRealUpperRamificationGroup_natCard
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n k : ℕ) (hk : 1 ≤ k) (hkn : k ≤ n + 1) :
    Nat.card
        (standardLubinTateRealUpperRamificationGroup hπ n (k : ℝ)) =
      Nat.card F.residueField ^ (n + 1 - k)
LubinTate.standardLubinTateRealLowerRamificationGroup_eq_break_of_pow_interval

On a lower-numbering power interval, the lower group is the group at the right endpoint q ^ k - 1.

Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem standardLubinTateRealLowerRamificationGroup_eq_break_of_pow_interval
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n k r : ℕ) (hk : 1 ≤ k) (hkn : k ≤ n + 1)
    (hlow : Nat.card F.residueField ^ (k - 1) ≤ r)
    (hhigh : r < Nat.card F.residueField ^ k) :
    standardLubinTateRealLowerRamificationGroup hπ n (r : ℝ) =
      standardLubinTateRealLowerRamificationGroup hπ n
        ((Nat.card F.residueField ^ k - 1 : ℕ) : ℝ)
LubinTate.standardLubinTateRealUpperRamificationGroup_eq_natCeil

On the positive range visible at level n + 1, the real upper filtration is the natural-ceiling extension of its integral values.

Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem standardLubinTateRealUpperRamificationGroup_eq_natCeil
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n : ℕ) (t : ℝ)
    (hk : 1 ≤ ⌈t⌉₊) (hkn : ⌈t⌉₊ ≤ n + 1) :
    standardLubinTateRealUpperRamificationGroup hπ n t =
      standardLubinTateRealUpperRamificationGroup
        hπ n (⌈t⌉₊ : ℝ)
LubinTate.standardLubinTateRealUpperRamificationGroup_eq_galoisParameterSubgroup_of_ceil

On the positive visible range, the real upper group is the Galois image at its natural-ceiling principal-unit level.

Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem
    standardLubinTateRealUpperRamificationGroup_eq_galoisParameterSubgroup_of_ceil
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n : ℕ) (t : ℝ)
    (hk : 1 ≤ ⌈t⌉₊) (hkn : ⌈t⌉₊ ≤ n + 1) :
    standardLubinTateRealUpperRamificationGroup hπ n t =
      standardLubinTateGaloisParameterSubgroup F hπ n ⌈t⌉₊
LubinTate.standardLubinTateRealUpperRamificationGroup_natCard_of_ceil

On the positive visible range, the real upper group has the order prescribed by its natural-ceiling principal-unit level.

Source context 10 commands

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

noncomputable section
universe u v
namespace LubinTate
open LocalFieldTheory.DiscreteValuationField
open LocalFieldTheory.DiscreteValuationField.CompleteDVF
open RamificationTheory.DiscreteValuationField
open RamificationTheory.HilbertRamification.Higher
variable {K : Type u} [Field K]
noncomputable local instance
    standardLubinTateLevelField_finiteDimensional_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    FiniteDimensional K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_finiteDimensional hπ n
noncomputable local instance
    standardLubinTateLevelField_isGalois_forHerbrandFormula
    {F : LocalField.{u, v} K} {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K)) (n : ℕ) :
    IsGalois K (standardLubinTateLevelField hπ n) :=
  standardLubinTateLevelField_isGalois hπ n
theorem standardLubinTateRealUpperRamificationGroup_natCard_of_ceil
    (F : LocalField.{u, v} K) {π : F.valuationSubring}
    (hπ : F.toCompleteDVF.valuation.IsUniformizer (π : K))
    (n : ℕ) (t : ℝ)
    (hk : 1 ≤ ⌈t⌉₊) (hkn : ⌈t⌉₊ ≤ n + 1) :
    Nat.card (standardLubinTateRealUpperRamificationGroup hπ n t) =
      Nat.card F.residueField ^ (n + 1 - ⌈t⌉₊)