Deligne's Proposition 2.1, over a category with an odd line #
If every object of a small abelian rigid symmetric monoidal ℂ-linear category with scalar unit endomorphisms is killed by some Schur functor, and its Ind-completion carries an odd line, then there is a nonzero commutative algebra in the Ind-completion whose fibre functor is strong monoidal, exact and faithful.
theorem
RS.exists_fibre_functor
{C : Type v}
[CategoryTheory.SmallCategory C]
[CategoryTheory.MonoidalCategory C]
[CategoryTheory.SymmetricCategory C]
[CategoryTheory.Abelian C]
[CategoryTheory.RigidCategory C]
[CategoryTheory.MonoidalPreadditive C]
(ψ : ℂ ≃+* CategoryTheory.End (CategoryTheory.MonoidalCategoryStruct.tensorUnit C))
(P : SchurPackage)
(P₀ : SchurPackage)
(L : OddLine (CategoryTheory.Ind C))
(hkill : ∀ (Z : C), ∃ (lam : YoungDiagram), SchurKilled P Z lam)
:
∃ (𝔸 : CategoryTheory.Ind C) (x : CategoryTheory.MonObj 𝔸) (x_1 : CategoryTheory.IsCommMonObj 𝔸),
CategoryTheory.MonObj.one ≠ 0 ∧ Nonempty (indOf.comp (fibreOver L 𝔸)).Monoidal ∧ Nonempty (CategoryTheory.Limits.PreservesFiniteLimits (indOf.comp (fibreFun L 𝔸))) ∧ Nonempty (CategoryTheory.Limits.PreservesFiniteColimits (indOf.comp (fibreFun L 𝔸))) ∧ (indOf.comp (fibreFun L 𝔸)).Faithful
Deligne's Proposition 2.1 for a category whose Ind-completion carries an odd line.