Higher-degree graded maps factor with neither factor split #
@[instance_reducible]
def
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.rdGradedHigherDegreeQuiver
{k A : Type u}
[Field k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
[IsNoetherianRing Aᵐᵒᵖ]
(S : FiniteIndecomposableSkeleton k A)
:
Quiver (Fin S.n)
Instances For
@[instance_reducible]
noncomputable def
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.rdGradedHigherDegreeArrowFintype
{k A : Type u}
[Field k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
[IsNoetherianRing Aᵐᵒᵖ]
(S : FiniteIndecomposableSkeleton k A)
(x y : Fin S.n)
:
Fintype (x ⟶ y)
Instances For
theorem
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.standardFormGraded_higherDegree_factorization
{k A : Type u}
[Field k]
[IsAlgClosed k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
[IsNoetherianRing Aᵐᵒᵖ]
(S : FiniteIndecomposableSkeleton k A)
(X Y : S.StandardFormMeshCategory)
(t : ℤ)
(n : ℕ)
(hn : 0 < n)
(f :
{ obj := S.standardFormGradedVertexFunctor.obj X, degree := t + ↑n + 1 } ⟶ { obj := S.standardFormGradedVertexFunctor.obj Y, degree := t })
:
f ∈ CategoryTheory.noBackwardFactorizations { obj := S.standardFormGradedVertexFunctor.obj X, degree := t + ↑n + 1 }
{ obj := S.standardFormGradedVertexFunctor.obj Y, degree := t }
Every map of degree n+1, n positive, factors through intermediate shifted modules admitting no reverse maps to either endpoint.
theorem
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.standardFormGraded_higherDegree_not_irreducible
{k A : Type u}
[Field k]
[IsAlgClosed k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
[IsNoetherianRing Aᵐᵒᵖ]
(S : FiniteIndecomposableSkeleton k A)
(X Y : S.StandardFormMeshCategory)
(t : ℤ)
(n : ℕ)
(hn : 0 < n)
(f :
{ obj := S.standardFormGradedVertexFunctor.obj X, degree := t + ↑n + 1 } ⟶ { obj := S.standardFormGradedVertexFunctor.obj Y, degree := t })
(hf : f ≠ 0)
:
Nonzero higher-degree maps are not irreducible.