Corollary 12.1: the radical grading of ind(mod B) is C #
deformation-refinements.tex: "The Hom normalization makes the M_i^B indecomposable and
pairwise nonisomorphic. Proposition 6.5(3) identifies their categorical radical grading with C."
Formalization. The hypotheses of Proposition 6.5(3) hold for the evaluated modules of A₀
(liftHyp, and the graded Hom category is generated in degree one, hgen), so the qth power
of the categorical radical of the lifted modules is the filtration order ≥ q
(mem_radPow_lifted). Leading terms identify rad^q / rad^{q+1} with the degree-q part of
C (leadL: surjective, kernel rad^{q+1}), compatibly with composition (leadC_comp).
The hypotheses of Proposition 6.5(3) #
The radical powers of ind(mod B) are the filtration orders (Proposition 6.5(3)).
Leading terms #
The leading term of a map of order ≥ r, a morphism of C of degree r.
Instances For
The leading-term map rad^r(M_X^B, M_Y^B) → C_r(X, Y).
Instances For
Leading terms are multiplicative: gr_J ind(mod B) ≅ C as categories.
Corollary 12.1 #
Corollary 12.1 (cor:positive-deformation-completeness) for mesh data whose positive
degrees are radical. Every positive filtered deformation B of A₀ is representation-finite;
the lifted modules M_x^B (which exist, Proposition 6.5) are indecomposable, pairwise
nonisomorphic and exhaust the indecomposable B-modules; the qth radical power of
ind(mod B) is the filtration order ≥ q, and leading terms identify rad^q / rad^{q+1} with
C_q, compatibly with composition: gr_J ind(mod B) ≅ C with these labels.
In k(Γ_A), morphisms of positive degree are radical.
Corollary 12.1 for the algebra A₀ of a basic representation-finite algebra A
(Construction 2.8): every positive filtered deformation B of A₀ is representation-finite,
the lifted modules M_x^B are a skeleton of ind(mod B), and gr_J ind(mod B) ≅ k(Γ_A) with
these labels.