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Atlas.TensorCategories.code.VecSemisimple

The ground field k, viewed as a one-dimensional vector space, is a simple object in FGModuleCat k: every monomorphism into it from a nonzero object is an iso.

An object X of FGModuleCat k that is not categorically zero is nontrivial as a vector space, i.e. it contains a nonzero element.

The morphism k ⟶ X sending 1 to a nonzero vector v ∈ X is itself nonzero in FGModuleCat k.

The morphism k ⟶ X sending 1 to a nonzero vector v ∈ X is a monomorphism in FGModuleCat k, since c ↦ c • v is injective when v ≠ 0.

Every simple object X in FGModuleCat k is isomorphic to the ground field k, since a nonzero vector spans a one-dimensional subspace which then forces an iso.

Instances For
    def VecSemisimple.ofHomAddHom (k : Type u) [Field k] (X Y : FGModuleCat k) :
    (X →ₗ[k] Y) →+ (X Y)

    The additive map sending a k-linear map X →ₗ[k] Y to its packaging as a morphism X ⟶ Y in FGModuleCat k.

    Instances For

      FGModuleCat k is a semisimple category: every finite-dimensional k-vector space splits as a direct sum of dim_k(X) copies of the simple object k.

      FGModuleCat k has finitely many isomorphism classes of simple objects, in fact exactly one: every simple object is isomorphic to the ground field k.

      Vec k = FGModuleCat k is a fusion category over k: it is a finite, semisimple, rigid k-linear tensor category whose unit has endomorphism algebra k.