Module

HilbertFamilyAlgEquiv.lean

Nyll.ClassFieldTheory.GlobalClassFieldTheory.Reciprocity.HilbertFamilyAlgEquiv
5 declarations indexed from sourceView source ↗

Hilbert-pairing families under equivalences of number fields

A number-field equivalence permutes finite places and identifies the corresponding adic completions. The local pairings and their finite factors can therefore be transported without changing their normalization.

Declarations

ClassFieldTheory.primitiveRoots_nonempty_adicCompletion

A primitive root in the number field remains primitive in every finite adic completion.

Source context 5 commands

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

open scoped NumberField
open NumberField IsDedekindDomain
noncomputable section
namespace ClassFieldTheory
universe u v
theorem primitiveRoots_nonempty_adicCompletion
    (F : Type u) [Field F] [NumberField F]
    (n : ℕ+) (hmu : (primitiveRoots (n : ℕ) F).Nonempty)
    (v : HeightOneSpectrum (𝓞 F)) :
    (primitiveRoots (n : ℕ) (v.adicCompletion F)).Nonempty
ClassFieldTheory.globalHilbertPairingFamilyCongr

Transport a global family through the finite-place and adic-completion equivalences induced by an equivalence of number fields.

Source context 5 commands

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

open scoped NumberField
open NumberField IsDedekindDomain
noncomputable section
namespace ClassFieldTheory
universe u v
def globalHilbertPairingFamilyCongr
    {F : Type u} {G : Type v}
    [Field F] [NumberField F] [Field G] [NumberField G]
    (e : F ≃ₐ[ℚ] G) (n : ℕ+)
    (hmuF : (primitiveRoots (n : ℕ) F).Nonempty)
    (BF : GlobalHilbertPairingFamily F n) :
    GlobalHilbertPairingFamily G n
ClassFieldTheory.globalHilbertPairingFamilyCongr_isLocallyHilbert

Local Hilbert-pairing laws survive transport of the global family.

Source context 5 commands

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

open scoped NumberField
open NumberField IsDedekindDomain
noncomputable section
namespace ClassFieldTheory
universe u v
theorem globalHilbertPairingFamilyCongr_isLocallyHilbert
    {F : Type u} {G : Type v}
    [Field F] [NumberField F] [Field G] [NumberField G]
    (e : F ≃ₐ[ℚ] G) (n : ℕ+)
    (hmuF : (primitiveRoots (n : ℕ) F).Nonempty)
    (BF : GlobalHilbertPairingFamily F n)
    (hBF : GlobalHilbertPairingFamily.IsLocallyHilbert F BF) :
    GlobalHilbertPairingFamily.IsLocallyHilbert G
      (globalHilbertPairingFamilyCongr e n hmuF BF)
ClassFieldTheory.globalHilbertPairingFamilyCongr_finiteFactor

At corresponding places, finite factors of the transported family are related by the equivalence of global roots of unity.

Source context 5 commands

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

open scoped NumberField
open NumberField IsDedekindDomain
noncomputable section
namespace ClassFieldTheory
universe u v
theorem globalHilbertPairingFamilyCongr_finiteFactor
    {F : Type u} {G : Type v}
    [Field F] [NumberField F] [Field G] [NumberField G]
    (e : F ≃ₐ[ℚ] G) (n : ℕ+)
    (hmuF : (primitiveRoots (n : ℕ) F).Nonempty)
    (hmuG : (primitiveRoots (n : ℕ) G).Nonempty)
    (BF : GlobalHilbertPairingFamily F n)
    (W : HeightOneSpectrum (𝓞 G)) (a b : Fˣ) :
    rootsOfUnityEquivOfRingEquiv e.toRingEquiv n hmuF
        (GlobalHilbertPairingFamily.finiteFactor F BF hmuF
          ((finitePlaceCongr e).symm W) a b) =
      GlobalHilbertPairingFamily.finiteFactor G
        (globalHilbertPairingFamilyCongr e n hmuF BF) hmuG W
        (Units.mapEquiv e.toRingEquiv.toMulEquiv a)
        (Units.mapEquiv e.toRingEquiv.toMulEquiv b)
ClassFieldTheory.globalHilbertPairingFamilyCongr_hasFiniteSupport

Finite support of global evaluations is invariant under an equivalence of number fields.

Source context 5 commands

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

open scoped NumberField
open NumberField IsDedekindDomain
noncomputable section
namespace ClassFieldTheory
universe u v
theorem globalHilbertPairingFamilyCongr_hasFiniteSupport
    {F : Type u} {G : Type v}
    [Field F] [NumberField F] [Field G] [NumberField G]
    (e : F ≃ₐ[ℚ] G) (n : ℕ+)
    (hmuF : (primitiveRoots (n : ℕ) F).Nonempty)
    (hmuG : (primitiveRoots (n : ℕ) G).Nonempty)
    (BF : GlobalHilbertPairingFamily F n)
    (hBF : GlobalHilbertPairingFamily.HasFiniteSupport F BF hmuF) :
    GlobalHilbertPairingFamily.HasFiniteSupport G
      (globalHilbertPairingFamilyCongr e n hmuF BF) hmuG