Module

RawOverlapSupplier.lean

Nyll.EtaleFundamentalGroups.FiniteEtale.FiniteField.RawOverlapSupplier
11 declarations indexed from sourceView source ↗

Raw Overlap Supplier

The literal coefficient extension of a local model, over its coefficient base.

Declarations

EtaleFundamentalGroups.coefficientLocalModelOver

The literal coefficient extension of a local model, over its coefficient base.

Source context 6 commands

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

noncomputable section
open CategoryTheory Limits Opposite AlgebraicGeometry
universe u
namespace EtaleFundamentalGroups
variable {T T' S U V Y : Scheme.{u}}
variable (φ : T' ⟶ T) (f : S ⟶ T) (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U)
abbrev coefficientLocalModelOver : Over T'
EtaleFundamentalGroups.coefficientOverlapOver

The literal coefficient extension of an overlap, over its coefficient base.

Source context 6 commands

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

noncomputable section
open CategoryTheory Limits Opposite AlgebraicGeometry
universe u
namespace EtaleFundamentalGroups
variable {T T' S U V Y : Scheme.{u}}
variable (φ : T' ⟶ T) (f : S ⟶ T) (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U)
abbrev coefficientOverlapOver : Over T'
EtaleFundamentalGroups.coefficientOverlapInclusion

The literal coefficient extension of the first overlap inclusion.

Source context 6 commands

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

noncomputable section
open CategoryTheory Limits Opposite AlgebraicGeometry
universe u
namespace EtaleFundamentalGroups
variable {T T' S U V Y : Scheme.{u}}
variable (φ : T' ⟶ T) (f : S ⟶ T) (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U)
def coefficientOverlapInclusion :
    coefficientOverlapOver φ f u v y ⟶ coefficientLocalModelOver φ f u y
EtaleFundamentalGroups.coefficientLocalModelStructure

The actual local-model map to the coefficient-extended base chart.

Source context 6 commands

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

noncomputable section
open CategoryTheory Limits Opposite AlgebraicGeometry
universe u
namespace EtaleFundamentalGroups
variable {T T' S U V Y : Scheme.{u}}
variable (φ : T' ⟶ T) (f : S ⟶ T) (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U)
def coefficientLocalModelStructure :
    (coefficientLocalModelOver φ f u y).left ⟶ pullback φ (u ≫ f)
EtaleFundamentalGroups.coefficientOverlapSecondMap

The actual second map of the coefficient-extended overlap.

Source context 6 commands

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

noncomputable section
open CategoryTheory Limits Opposite AlgebraicGeometry
universe u
namespace EtaleFundamentalGroups
variable {T T' S U V Y : Scheme.{u}}
variable (φ : T' ⟶ T) (f : S ⟶ T) (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U)
def coefficientOverlapSecondMap :
    (coefficientOverlapOver φ f u v y).left ⟶ pullback φ (v ≫ f)
EtaleFundamentalGroups.coefficientOverlap_isPullback

The raw coefficient-extended overlap is cartesian over the extended cover.

Source context 6 commands

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

noncomputable section
open CategoryTheory Limits Opposite AlgebraicGeometry
universe u
namespace EtaleFundamentalGroups
variable {T T' S U V Y : Scheme.{u}}
variable (φ : T' ⟶ T) (f : S ⟶ T) (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U)
theorem coefficientOverlap_isPullback :
    IsPullback (coefficientOverlapInclusion φ f u v y).left
      (coefficientOverlapSecondMap φ f u v y)
      (coefficientLocalModelStructure φ f u y ≫ coefficientModelMap φ f u)
      (coefficientModelMap φ f v)
EtaleFundamentalGroups.coefficientLocalModelStructure_isPullback

The local model structure is the actual base change of the original one.

Source context 6 commands

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

noncomputable section
open CategoryTheory Limits Opposite AlgebraicGeometry
universe u
namespace EtaleFundamentalGroups
variable {T T' S U V Y : Scheme.{u}}
variable (φ : T' ⟶ T) (f : S ⟶ T) (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U)
theorem coefficientLocalModelStructure_isPullback :
    IsPullback (coefficientLocalModelStructure φ f u y)
      (pullback.snd φ ((y ≫ u) ≫ f))
      (pullback.snd φ (u ≫ f)) y
EtaleFundamentalGroups.coefficientLocalModelStructure_finiteEtale

Actual finite étale local models remain finite étale on the literal extension.

Source context 6 commands

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

noncomputable section
open CategoryTheory Limits Opposite AlgebraicGeometry
universe u
namespace EtaleFundamentalGroups
variable {T T' S U V Y : Scheme.{u}}
variable (φ : T' ⟶ T) (f : S ⟶ T) (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U)
theorem coefficientLocalModelStructure_finiteEtale [IsFiniteEtale y] :
    IsFiniteEtale (coefficientLocalModelStructure φ f u y)
EtaleFundamentalGroups.coefficientLocalModelStructure_base

The local structure and chart inclusion agree with the literal total-model map.

Source context 6 commands

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

noncomputable section
open CategoryTheory Limits Opposite AlgebraicGeometry
universe u
namespace EtaleFundamentalGroups
variable {T T' S U V Y : Scheme.{u}}
variable (φ : T' ⟶ T) (f : S ⟶ T) (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U)
theorem coefficientLocalModelStructure_base :
    coefficientLocalModelStructure φ f u y ≫ coefficientModelMap φ f u =
      coefficientModelMap φ f (y ≫ u)
EtaleFundamentalGroups.coefficientOverlapInclusion_base

The first overlap inclusion preserves the actual map to the extended base.

Source context 6 commands

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

noncomputable section
open CategoryTheory Limits Opposite AlgebraicGeometry
universe u
namespace EtaleFundamentalGroups
variable {T T' S U V Y : Scheme.{u}}
variable (φ : T' ⟶ T) (f : S ⟶ T) (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U)
theorem coefficientOverlapInclusion_base :
    (coefficientOverlapInclusion φ f u v y).left ≫
        coefficientLocalModelStructure φ f u y ≫ coefficientModelMap φ f u =
      coefficientModelMap φ f (pullback.fst (y ≫ u) v ≫ (y ≫ u))
EtaleFundamentalGroups.coefficientOverlapFirstMap_stage_naturality

The actual coefficient cone maps preserve the first overlap inclusions.

Source context 13 commands

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

noncomputable section
open CategoryTheory Limits Opposite AlgebraicGeometry
universe u
namespace EtaleFundamentalGroups
variable {T T' S U V Y : Scheme.{u}}
variable (φ : T' ⟶ T) (f : S ⟶ T) (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U)
section FieldStage
variable (k L : Type u) [Field k] [Field L] [Algebra k L]
variable (S U V Y : Scheme.{u}) (f : S ⟶ Spec (CommRingCat.of k))
variable (u : U ⟶ S) (v : V ⟶ S) (y : Y ⟶ U) (s : Finset L)
local notation "φL" => Spec.map (CommRingCat.ofHom (algebraMap k L))
local notation "φE" => Spec.map (CommRingCat.ofHom
  (algebraMap k (IntermediateField.adjoin k (s : Set L))))
local notation "p" => (pullback.fst (y ≫ u) v ≫ (y ≫ u))
theorem coefficientOverlapFirstMap_stage_naturality :
    (constantFieldInverseLimitCone k L (pullback (y ≫ u) v) (p ≫ f)).π.app (op s) ≫
        coefficientOverlapFirstMap φE f u v y =
      coefficientOverlapFirstMap φL f u v y ≫
        (constantFieldInverseLimitCone k L Y ((y ≫ u) ≫ f)).π.app (op s)