Magnitude conjecture

MagnitudeConjecture.Algebra.RightModuleCoherentCodefectEvaluation

Evaluating the contravariant defect #

Evaluation is exact on the finite linear functor category. Consequently the value of the contravariant defect at Xᵒᵖ is the ordinary quotient

Hom(X, C) / im(Hom(X, B) → Hom(X, C))

attached to the second map B → C of the module complex.

def MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.finiteContravariantFunctorInclusion {k A : Type u} [Field k] [Ring A] [Algebra k A] (S : FiniteIndecomposableSkeleton k A) :
CategoryTheory.Functor S.FiniteContravariantFunctor (CategoryTheory.Functor S.IndecCategoryᵒᵖ (ModuleCat k))

Forget the finite-dimensional and linear-property wrappers.

Instances For
    def MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.finiteContravariantFunctorEvaluation {k A : Type u} [Field k] [Ring A] [Algebra k A] (S : FiniteIndecomposableSkeleton k A) (X : S.IndecCategoryᵒᵖ) :
    CategoryTheory.Functor S.FiniteContravariantFunctor (ModuleCat k)

    Evaluation of a finite contravariant functor at a chosen indecomposable.

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      @[reducible, inline]
      abbrev MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.finiteContravariantPresentationRange {k A : Type u} [Field k] [Ring A] [Algebra k A] (S : FiniteIndecomposableSkeleton k A) (K : CategoryTheory.ShortComplex FG) (X : S.IndecCategory) :
      Submodule k ((S.fgObj X).obj ⟶ K.X₃.obj)

      The ambient module-theoretic presentation coboundaries obtained by postcomposing with the second map of K.

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        theorem MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.finiteContravariantFunctorEvaluation_map_range {k A : Type u} [Field k] [Ring A] [Algebra k A] [FiniteDimensional k A] [IsNoetherianRing Aᵐᵒᵖ] (S : FiniteIndecomposableSkeleton k A) (K : CategoryTheory.ShortComplex FG) (X : S.IndecCategory) :

        Evaluating the contravariant representable map gives the ordinary postcomposition map in the module category.

        noncomputable def MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.finiteContravariantDefectEvaluationIsoPresentationQuotient {k A : Type u} [Field k] [Ring A] [Algebra k A] [FiniteDimensional k A] [IsNoetherianRing Aᵐᵒᵖ] (S : FiniteIndecomposableSkeleton k A) (K : CategoryTheory.ShortComplex FG) (X : S.IndecCategory) :
        (S.finiteContravariantDefect K).obj.obj.obj (Opposite.op X) ≅ ModuleCat.of k (((S.fgObj X).obj ⟶ K.X₃.obj) ⧸ S.finiteContravariantPresentationRange K X)

        The value of the contravariant defect is the module-presentation quotient.

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          noncomputable def MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.finiteContravariantDefectEvaluationLinearEquivPresentationQuotient {k A : Type u} [Field k] [Ring A] [Algebra k A] [FiniteDimensional k A] [IsNoetherianRing Aᵐᵒᵖ] (S : FiniteIndecomposableSkeleton k A) (K : CategoryTheory.ShortComplex FG) (X : S.IndecCategory) :
          ↑((S.finiteContravariantDefect K).obj.obj.obj (Opposite.op X)) ≃ₗ[k] ((S.fgObj X).obj ⟶ K.X₃.obj) ⧸ S.finiteContravariantPresentationRange K X

          Linear-equivalence form of the evaluated contravariant-defect calculation.

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