Uniform incoming Hom bounds for the graded standard form #
theorem
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.standardFormGraded_incoming_shift_bounds
{k A : Type u}
[Field k]
[IsAlgClosed k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
[IsNoetherianRing Aᵐᵒᵖ]
(S : FiniteIndecomposableSkeleton k A)
(h : ℕ)
(hb :
∀ (X Y : S.StandardFormMeshCategory) (d : ℤ), d < 0 ∨ ↑h < d → S.standardFormIntegerHomGrading.component X Y d = ⊥)
(X Y : S.StandardFormMeshCategory)
(s t : ℤ)
(f :
{ obj := S.standardFormGradedVertexFunctor.obj X, degree := s } ⟶ { obj := S.standardFormGradedVertexFunctor.obj Y, degree := t })
(hf : f ≠ 0)
:
t ≤ s ∧ s ≤ t + ↑h
A common bound on homogeneous degrees bounds the source shift of every nonzero incoming map, including maps between equal vertex labels.
theorem
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.standardFormGraded_hom_finrank_le
{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)
(s t : ℤ)
:
Module.finrank k
({ obj := S.standardFormGradedVertexFunctor.obj X, degree := s } ⟶ { obj := S.standardFormGradedVertexFunctor.obj Y, degree := t }) ≤ Module.finrank k (X ⟶ Y)
Hom dimensions of shifted vertex modules are bounded by the fixed ungraded mesh Hom dimension, independently of both shifts.