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Equivalence to brick-finiteness for tame algebras

Ascertain whether, for every tame finite-dimensional algebra A over an algebraically closed field, brick-finiteness is equivalent to each of the following five conditions: (i) A is brick-discrete; (ii) A is E-finite; (iii) A is stably-discrete; (iv) the Auslander–Reiten quiver Γ_A has no generalized standard components; and (v) Γ_A has no infinite family of Hom-orthogonal tubes whose quasi-simple modules all have the same dimension.

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Background

The authors prove an equivalence of five conditions for tame algebras (brick-discrete, E-finite, stably-discrete, absence of generalized standard components, and absence of certain Hom-orthogonal tube families). They note that the 2nd bBT conjecture remains open for arbitrary tame algebras and highlight an additional unresolved equivalence to brick-finiteness.

Settling this would complete the equivalence diagram for tame algebras, tying geometric, homological, and Auslander–Reiten–theoretic properties directly to brick-finiteness.

References

With regard to Theorem \ref{Thm: equivalences for tame algebras}, we remark that although the 2nd bBT (see Conjecture \ref{2nd bBT Conj.}) is verified for some important families of tame algebras, the conjecture is still open for arbitrary tame algebras. More specifically, it is still not known whether the above $5$ conditions are also equivalent to $A$ being brick-finite.

On the bricks (Schur representations) of finite dimensional algebras (2508.11789 - Mousavand et al., 15 Aug 2025) in Remark following Theorem on tame equivalences (Theorem 6.x), Section 6