Module

FiniteMathlibTopologyComparison.lean

Nyll.ClassFieldTheory.AlgebraicNumberTheory.Idele.FiniteMathlibTopologyComparison
5 declarations indexed from sourceView source ↗

The finite idèle topology and adele units

The algebraic equivalence from finite idèles to units of the finite adele ring is continuous for the restricted-product topology on idèles and the graph topology on units. Both the value and inverse-value maps are induced by continuous maps on local factors.

Declarations

IdeleGroup.finiteEquivFiniteAdeleUnitsContinuousMulEquiv

The finite restricted-product idèles and finite adele units are canonically isomorphic as topological groups.

Source context 5 commands

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

open scoped NumberField RestrictedProduct
open NumberField IsDedekindDomain
noncomputable section
namespace IdeleGroup
variable (K : Type*) [Field K] [NumberField K]
def finiteEquivFiniteAdeleUnitsContinuousMulEquiv :
    FiniteIdeleGroup K ≃ₜ*
      (IsDedekindDomain.FiniteAdeleRing (𝓞 K) K)ˣ
IdeleGroup.finiteEquivFiniteAdeleUnitsContinuousMulEquiv_apply

The topological and algebraic finite-idèle comparisons agree pointwise.

Source context 5 commands

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

open scoped NumberField RestrictedProduct
open NumberField IsDedekindDomain
noncomputable section
namespace IdeleGroup
variable (K : Type*) [Field K] [NumberField K]
theorem finiteEquivFiniteAdeleUnitsContinuousMulEquiv_apply
    (a : FiniteIdeleGroup K) :
    finiteEquivFiniteAdeleUnitsContinuousMulEquiv K a =
      finiteEquivFiniteAdeleUnits a
IdeleGroup.continuous_finiteEquivFiniteAdeleUnits

The algebraic finite-idèle comparison is continuous in the forward direction.

Source context 5 commands

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

open scoped NumberField RestrictedProduct
open NumberField IsDedekindDomain
noncomputable section
namespace IdeleGroup
variable (K : Type*) [Field K] [NumberField K]
theorem continuous_finiteEquivFiniteAdeleUnits :
    Continuous (finiteEquivFiniteAdeleUnits (K := K))
IdeleGroup.continuous_equivAdeleRingUnits

The algebraic equivalence from restricted-product idèles to adele units is continuous in the forward direction.

Source context 5 commands

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

open scoped NumberField RestrictedProduct
open NumberField IsDedekindDomain
noncomputable section
namespace IdeleGroup
variable (K : Type*) [Field K] [NumberField K]
theorem continuous_equivAdeleRingUnits :
    Continuous (equivAdeleRingUnits (K := K))
IdeleGroup.equivAdeleRingUnitsContinuousMulEquiv

The full restricted-product idèle group is canonically isomorphic to Mathlib's adele-unit idèle group as a topological group.

Source context 5 commands

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

open scoped NumberField RestrictedProduct
open NumberField IsDedekindDomain
noncomputable section
namespace IdeleGroup
variable (K : Type*) [Field K] [NumberField K]
def equivAdeleRingUnitsContinuousMulEquiv :
    IdeleGroup K ≃ₜ* (NumberField.AdeleRing (𝓞 K) K)ˣ