Biserial primitive-projective presentations #
A finite-dimensional algebra is biserial when the principal right and left ideals belonging to a complete family of primitive orthogonal idempotents are biserial modules. This file records that condition on the literal primitive-projective presentations used by the support-quotient construction.
def
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.PrimitiveProjectivePresentation.IsBiserial
{k A : Type u}
[Field k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
[IsNoetherianRing A]
[IsNoetherianRing Aᵐᵒᵖ]
{S : FiniteIndecomposableSkeleton k A}
(P : S.PrimitiveProjectivePresentation)
:
A complete primitive-projective presentation is biserial when every
associated principal right ideal eA and principal left ideal Ae is a
biserial object.
Instances For
theorem
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.PrimitiveProjectivePresentation.IsBiserial.rightIdeal_top_jacobson_length_le_two
{k A : Type u}
[Field k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
[IsNoetherianRing A]
[IsNoetherianRing Aᵐᵒᵖ]
{S : FiniteIndecomposableSkeleton k A}
{P : S.PrimitiveProjectivePresentation}
(hP : P.IsBiserial)
(p : S.ProjectiveLabel)
:
Module.length Aᵐᵒᵖ
(↥(Module.jacobson Aᵐᵒᵖ ↑(rightIdealFGObj (P.idempotent p))) ⧸ Module.jacobson Aᵐᵒᵖ ↥(Module.jacobson Aᵐᵒᵖ ↑(rightIdealFGObj (P.idempotent p)))) ≤ 2
Biseriality of a primitive-projective presentation bounds the first radical layer of every associated principal right ideal by two.
theorem
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.PrimitiveProjectivePresentation.IsBiserial.leftIdeal_top_jacobson_length_le_two
{k A : Type u}
[Field k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
[IsNoetherianRing A]
[IsNoetherianRing Aᵐᵒᵖ]
{S : FiniteIndecomposableSkeleton k A}
{P : S.PrimitiveProjectivePresentation}
(hP : P.IsBiserial)
(p : S.ProjectiveLabel)
:
Module.length A
(↥(Module.jacobson A ↑(leftIdealFGObj (P.idempotent p))) ⧸ Module.jacobson A ↥(Module.jacobson A ↑(leftIdealFGObj (P.idempotent p)))) ≤ 2
Biseriality of a primitive-projective presentation bounds the first radical layer of every associated principal left ideal by two.