Homogeneous direct-sum coordinates for finite matrix objects #
noncomputable def
MagnitudeConjecture.GradedCategory.HomGrading.matrixBicone
{C : Type v}
[CategoryTheory.Category.{w, v} C]
[CategoryTheory.Preadditive C]
(M : CategoryTheory.Mat_ C)
:
CategoryTheory.Limits.Bicone fun (i : M.ι) => (CategoryTheory.Mat_.embedding C).obj (M.X i)
The matrix object with its singleton summand injections and projections.
Instances For
theorem
MagnitudeConjecture.GradedCategory.HomGrading.matrixBicone_total
{C : Type v}
[CategoryTheory.Category.{w, v} C]
[CategoryTheory.Preadditive C]
(M : CategoryTheory.Mat_ C)
:
∑ i : M.ι, CategoryTheory.CategoryStruct.comp ((matrixBicone M).π i) ((matrixBicone M).ι i) = CategoryTheory.CategoryStruct.id M
theorem
MagnitudeConjecture.GradedCategory.HomGrading.matrixBicone_π_homogeneous
{k : Type u}
[Field k]
{C : Type v}
[CategoryTheory.Category.{w, v} C]
[CategoryTheory.Preadditive C]
[CategoryTheory.Linear k C]
(G : HomGrading k C)
[∀ (X Y : C), FiniteDimensional k (X ⟶ Y)]
(M : CategoryTheory.Mat_ C)
(i : M.ι)
:
(matrixBicone M).π i ∈ G.additiveEnvelope.component M ((CategoryTheory.Mat_.embedding C).obj (M.X i)) 0
The singleton projections have degree zero.
theorem
MagnitudeConjecture.GradedCategory.HomGrading.matrixBicone_ι_homogeneous
{k : Type u}
[Field k]
{C : Type v}
[CategoryTheory.Category.{w, v} C]
[CategoryTheory.Preadditive C]
[CategoryTheory.Linear k C]
(G : HomGrading k C)
[∀ (X Y : C), FiniteDimensional k (X ⟶ Y)]
(M : CategoryTheory.Mat_ C)
(i : M.ι)
:
(matrixBicone M).ι i ∈ G.additiveEnvelope.component ((CategoryTheory.Mat_.embedding C).obj (M.X i)) M 0
The singleton injections have degree zero.