Module

IdeleCharacterGlobalLift.lean

Nyll.SawinTotallyRealTowers.UnramifiedProPRelationRank.Global.IdeleCharacterGlobalLift
11 declarations indexed from sourceView source ↗

Lifting an idele character to an absolute Galois character

A continuous finite-valued idele character trivial on principal ideles descends first to the idele class group and then to its component quotient. Actual global reciprocity identifies that quotient with the maximal abelian Galois group. Restriction from the absolute Galois group therefore gives a genuine continuous degree-one class.

Declarations

ClassFieldTower.Martinet.Shafarevich.ideleGlobalLiftTopology
Source context 5 commands

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

open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.ProP GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F] (p : ℕ) [Fact p.Prime]
instance ideleGlobalLiftTopology : TopologicalSpace (ZMod p)
ClassFieldTower.Martinet.Shafarevich.ideleGlobalLiftDiscreteTopology
Source context 6 commands

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

open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.ProP GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F] (p : ℕ) [Fact p.Prime]
local instance ideleGlobalLiftTopology : TopologicalSpace (ZMod p) := ⊥
instance ideleGlobalLiftDiscreteTopology : DiscreteTopology (ZMod p)
ClassFieldTower.Martinet.Shafarevich.ideleCharacterClassLift

Descent of a principal-trivial continuous character to the actual idele class group.

Source context 9 commands

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

open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.ProP GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F] (p : ℕ) [Fact p.Prime]
local instance ideleGlobalLiftTopology : TopologicalSpace (ZMod p) := ⊥
local instance ideleGlobalLiftDiscreteTopology : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
variable (chi : IdeleGroup F →ₜ* Multiplicative (ZMod p))
variable (hchi : ∀ a : Fˣ, chi (IdeleGroup.principalIdele F a) = 1)
def ideleCharacterClassLift : IdeleClassGroup F →ₜ* Multiplicative (ZMod p)
ClassFieldTower.Martinet.Shafarevich.ideleCharacterClassLift_mk
Source context 9 commands

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

open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.ProP GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F] (p : ℕ) [Fact p.Prime]
local instance ideleGlobalLiftTopology : TopologicalSpace (ZMod p) := ⊥
local instance ideleGlobalLiftDiscreteTopology : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
variable (chi : IdeleGroup F →ₜ* Multiplicative (ZMod p))
variable (hchi : ∀ a : Fˣ, chi (IdeleGroup.principalIdele F a) = 1)
theorem ideleCharacterClassLift_mk (a : IdeleGroup F) :
    ideleCharacterClassLift F p chi hchi
      (QuotientGroup.mk' (IdeleGroup.principalSubgroup F) a) = chi a
ClassFieldTower.Martinet.Shafarevich.ideleCharacterComponentLift

The character kills the connected component because its target is discrete.

Source context 9 commands

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

open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.ProP GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F] (p : ℕ) [Fact p.Prime]
local instance ideleGlobalLiftTopology : TopologicalSpace (ZMod p) := ⊥
local instance ideleGlobalLiftDiscreteTopology : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
variable (chi : IdeleGroup F →ₜ* Multiplicative (ZMod p))
variable (hchi : ∀ a : Fˣ, chi (IdeleGroup.principalIdele F a) = 1)
def ideleCharacterComponentLift :
    ideleClassComponentQuotient F →ₜ* Multiplicative (ZMod p)
ClassFieldTower.Martinet.Shafarevich.ideleCharacterComponentLift_mk
Source context 9 commands

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

open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.ProP GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F] (p : ℕ) [Fact p.Prime]
local instance ideleGlobalLiftTopology : TopologicalSpace (ZMod p) := ⊥
local instance ideleGlobalLiftDiscreteTopology : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
variable (chi : IdeleGroup F →ₜ* Multiplicative (ZMod p))
variable (hchi : ∀ a : Fˣ, chi (IdeleGroup.principalIdele F a) = 1)
theorem ideleCharacterComponentLift_mk (c : IdeleClassGroup F) :
    ideleCharacterComponentLift F p chi hchi
      (QuotientGroup.mk' (ideleClassIdentityComponent F) c) =
      ideleCharacterClassLift F p chi hchi c
ClassFieldTower.Martinet.Shafarevich.ideleCharacterMaximalAbelianLift

The character transported through the actual component-quotient reciprocity isomorphism.

Source context 9 commands

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

open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.ProP GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F] (p : ℕ) [Fact p.Prime]
local instance ideleGlobalLiftTopology : TopologicalSpace (ZMod p) := ⊥
local instance ideleGlobalLiftDiscreteTopology : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
variable (chi : IdeleGroup F →ₜ* Multiplicative (ZMod p))
variable (hchi : ∀ a : Fˣ, chi (IdeleGroup.principalIdele F a) = 1)
def ideleCharacterMaximalAbelianLift :
    Gal(maximalAbelianExtension F / F) →ₜ* Multiplicative (ZMod p)
ClassFieldTower.Martinet.Shafarevich.ideleCharacterMaximalAbelianLift_artin

Reciprocity sends an idele class back to the value of its descended character.

Source context 9 commands

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

open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.ProP GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F] (p : ℕ) [Fact p.Prime]
local instance ideleGlobalLiftTopology : TopologicalSpace (ZMod p) := ⊥
local instance ideleGlobalLiftDiscreteTopology : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
variable (chi : IdeleGroup F →ₜ* Multiplicative (ZMod p))
variable (hchi : ∀ a : Fˣ, chi (IdeleGroup.principalIdele F a) = 1)
theorem ideleCharacterMaximalAbelianLift_artin (c : IdeleClassGroup F) :
    ideleCharacterMaximalAbelianLift F p chi hchi (maximalAbelianGlobalArtin F c) =
      ideleCharacterClassLift F p chi hchi c
ClassFieldTower.Martinet.Shafarevich.ideleCharacterGlobalLift

A principal-trivial idele character gives an actual absolute Galois character.

Source context 9 commands

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

open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.ProP GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F] (p : ℕ) [Fact p.Prime]
local instance ideleGlobalLiftTopology : TopologicalSpace (ZMod p) := ⊥
local instance ideleGlobalLiftDiscreteTopology : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
variable (chi : IdeleGroup F →ₜ* Multiplicative (ZMod p))
variable (hchi : ∀ a : Fˣ, chi (IdeleGroup.principalIdele F a) = 1)
def ideleCharacterGlobalLift :
    Field.absoluteGaloisGroup F →ₜ* Multiplicative (ZMod p)
ClassFieldTower.Martinet.Shafarevich.ideleCharacterGlobalH1

The resulting continuous degree-one class of the absolute Galois group.

Source context 9 commands

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

open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.ProP GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F] (p : ℕ) [Fact p.Prime]
local instance ideleGlobalLiftTopology : TopologicalSpace (ZMod p) := ⊥
local instance ideleGlobalLiftDiscreteTopology : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
variable (chi : IdeleGroup F →ₜ* Multiplicative (ZMod p))
variable (hchi : ∀ a : Fˣ, chi (IdeleGroup.principalIdele F a) = 1)
def ideleCharacterGlobalH1 : ContinuousH1ZMod (p := p) (G := Field.absoluteGaloisGroup F)
ClassFieldTower.Martinet.Shafarevich.ideleCharacterGlobalH1_character
Source context 9 commands

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

open scoped NumberField Topology
noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
open ClassFieldTower.ProP GlobalClassFieldTheory.Reciprocity
variable (F : Type) [Field F] [NumberField F] (p : ℕ) [Fact p.Prime]
local instance ideleGlobalLiftTopology : TopologicalSpace (ZMod p) := ⊥
local instance ideleGlobalLiftDiscreteTopology : DiscreteTopology (ZMod p) :=
  discreteTopology_bot _
variable (chi : IdeleGroup F →ₜ* Multiplicative (ZMod p))
variable (hchi : ∀ a : Fˣ, chi (IdeleGroup.principalIdele F a) = 1)
theorem ideleCharacterGlobalH1_character :
    characterOfH1 (ideleCharacterGlobalH1 F p chi hchi) =
      ideleCharacterGlobalLift F p chi hchi