quotientRestriction
A compatible restriction of concrete embedded Galois actions induces the corresponding restriction map on ambient finite quotient representatives.
Source context 5 commands
Surrounding namespaces, section variables, and local commands at this declaration.
noncomputable section
namespace LocalClassFieldTheory
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation
open scoped IsMulCommutative ValuativeReltheorem AmbientEmbeddedFixedFieldPresentation.quotientRestriction
(K K' L L' : Type)
[Field K] [ValuativeRel K] [TopologicalSpace K]
[IsNonarchimedeanLocalField K]
[Field K'] [ValuativeRel K'] [TopologicalSpace K']
[IsNonarchimedeanLocalField K']
[Field L] [Field L']
[Algebra K K'] [Algebra K L] [Algebra K L']
[Algebra K' L'] [Algebra L L']
[IsScalarTower K K' L'] [IsScalarTower K L L']
[FiniteDimensional K K'] [Algebra.IsSeparable K K']
[Valuation.HasExtension
(ValuativeRel.valuation K) (ValuativeRel.valuation K')]
[FiniteDimensional K L] [IsAbelianGalois K L]
[FiniteDimensional K' L'] [IsAbelianGalois K' L']
{jLower : L →ₐ[K] SeparableClosure K}
{jUpper : L' →ₐ[K] SeparableClosure K}
(lower : AmbientEmbeddedFixedFieldPresentation K K L jLower)
(upper : AmbientEmbeddedFixedFieldPresentation K K' L' jUpper)
(hH'H : upper.base.field.toSubgroup ≤ lower.base.field.toSubgroup)
(hJ'J : upper.extension.field.toSubgroup ≤
lower.extension.field.toSubgroup)
[hJnormal :
(extensionSubgroup lower.base.field lower.extension.field
lower.extension.below).Normal]
[_hJfinite : Finite
(lower.base.field.toSubgroup ⧸
extensionSubgroup lower.base.field lower.extension.field
lower.extension.below)]
[hJ'normal :
(extensionSubgroup upper.base.field upper.extension.field
upper.extension.below).Normal]
[_hJ'finite : Finite
(upper.base.field.toSubgroup ⧸
extensionSubgroup upper.base.field upper.extension.field
upper.extension.below)]
[_hHabsolute : Finite
((baseField Gal(SeparableClosure K/K)).toSubgroup ⧸
extensionSubgroup
(baseField Gal(SeparableClosure K/K))
lower.base.field (le_baseField lower.base.field))]
[_hH'absolute : Finite
((baseField Gal(SeparableClosure K/K)).toSubgroup ⧸
extensionSubgroup
(baseField Gal(SeparableClosure K/K))
upper.base.field (le_baseField upper.base.field))]
[_hH'finite : Finite
(lower.base.field.toSubgroup ⧸
extensionSubgroup lower.base.field upper.base.field hH'H)]
(restrictActual : Gal(L'/K') →* Gal(L/K))
(hbase : ∀ x : L,
jUpper (algebraMap L L' x) = jLower x)
(hcompat : ∀ (τ : Gal(L' / K')) (x : L),
jLower (restrictActual τ x) =
jUpper (τ (algebraMap L L' x)))
(z : Abelianization
(upper.base.field.toSubgroup ⧸
extensionSubgroup upper.base.field upper.extension.field
upper.extension.below)) :
restrictActual
((Abelianization.equivOfComm (H := Gal(L' / K'))).symm
((upper.extension.extensionQuotientMulEquiv.symm.trans
upper.quotientEquiv).abelianizationCongr z)) =
(Abelianization.equivOfComm (H := Gal(L / K))).symm
((lower.extension.extensionQuotientMulEquiv.symm.trans
lower.quotientEquiv).abelianizationCongr
(normResidueNaturalityAbelianizedRestriction
lower.base.field upper.base.field
lower.extension.field upper.extension.field
lower.extension.below upper.extension.below
hH'H hJ'J z))