Module

NativeSectionRestriction.lean

Nyll.SchemeTheory.Modules.NativeSectionRestriction
12 declarations indexed from sourceView source ↗

Native section restriction maps

Uses the existing section rings and modules to represent their actual restriction maps.

Imports6
  • Mathlib.AlgebraicGeometry.Scheme
  • Mathlib.AlgebraicGeometry.Modules.Sheaf
  • Mathlib.Algebra.Category.ModuleCat.Basic
  • Mathlib.Algebra.Category.ModuleCat.ChangeOfRings
  • Mathlib.Algebra.Category.Grp.Basic
  • Mathlib.Algebra.Category.Ring.Basic
Imported by1

Declarations

AlgebraicGeometry.Scheme.Modules.NativeSections.sectionRing

The actual ring of sections at an open.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
def sectionRing (X : Scheme.{u}) (U : X.Opens) : CommRingCat.{u}
AlgebraicGeometry.Scheme.Modules.NativeSections.sectionModule

The actual module object, with its existing section-ring action.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
def sectionModule {X : Scheme.{u}} (M : X.Modules) (U : X.Opens) :
    ModuleCat.{u} (sectionRing X U)
AlgebraicGeometry.Scheme.Modules.NativeSections.sectionGroup

The actual abelian section-group object.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
def sectionGroup {X : Scheme.{u}} (M : X.Modules) (U : X.Opens) : AddCommGrpCat.{u}
AlgebraicGeometry.Scheme.Modules.NativeSections.ringRestriction

The actual section-ring restriction homomorphism.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
def ringRestriction {X : Scheme.{u}} {U V : X.Opens} (h : V ≤ U) :
    sectionRing X U →+* sectionRing X V
AlgebraicGeometry.Scheme.Modules.NativeSections.restrictedModule

The actual local module viewed through the prescribed section restriction.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
def restrictedModule {X : Scheme.{u}} (M : X.Modules) {U V : X.Opens} (h : V ≤ U) :
    ModuleCat.{u} (sectionRing X U)
AlgebraicGeometry.Scheme.Modules.NativeSections.restriction

The native presheaf restriction morphism, without projecting its carrier.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
def restriction {X : Scheme.{u}} (M : X.Modules) {U V : X.Opens} (h : V ≤ U) :
    sectionModule M U ⟶ restrictedModule M h
AlgebraicGeometry.Scheme.Modules.NativeSections.restrictionFn

The function underlying that same native restriction.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
def restrictionFn {X : Scheme.{u}} (M : X.Modules) {U V : X.Opens} (h : V ≤ U) :
    sectionGroup M U → sectionGroup M V
AlgebraicGeometry.Scheme.Modules.NativeSections.sourcePowFn

The existing source action, exposed only as its actual power function.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
def sourcePowFn {X : Scheme.{u}} (M : X.Modules) (U : X.Opens)
    (f : sectionRing X U) (n : ℕ) : sectionGroup M U → sectionGroup M U
AlgebraicGeometry.Scheme.Modules.NativeSections.restrictedPowFn

The existing restricted action, exposed only as its actual power function.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
def restrictedPowFn {X : Scheme.{u}} (M : X.Modules) {U V : X.Opens} (h : V ≤ U)
    (f : sectionRing X U) (n : ℕ) : sectionGroup M V → sectionGroup M V
AlgebraicGeometry.Scheme.Modules.NativeSections.restrictionFn_apply

Literal computation against the original abelian restriction map.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
theorem restrictionFn_apply {X : Scheme.{u}} (M : X.Modules) {U V : X.Opens}
    (h : V ≤ U) (x : Γ(M, U)) :
    restrictionFn M h x = M.presheaf.map (homOfLE h).op x
AlgebraicGeometry.Scheme.Modules.NativeSections.sourcePowFn_apply

Literal computation against the original source action.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
theorem sourcePowFn_apply {X : Scheme.{u}} (M : X.Modules) (U : X.Opens)
    (f : Γ(X, U)) (n : ℕ) (x : Γ(M, U)) :
    sourcePowFn M U f n x = f ^ n • x
AlgebraicGeometry.Scheme.Modules.NativeSections.restrictedPowFn_apply

Literal computation of the prescribed restriction-of-scalars action.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory TopologicalSpace Opposite
namespace AlgebraicGeometry.Scheme.Modules.NativeSections
theorem restrictedPowFn_apply {X : Scheme.{u}} (M : X.Modules) {U V : X.Opens}
    (h : V ≤ U) (f : Γ(X, U)) (n : ℕ) (x : Γ(M, V)) :
    restrictedPowFn M h f n x = X.presheaf.map (homOfLE h).op (f ^ n) • x