Publishing house / Journals and Serials / Fundamenta Mathematicae / All issues

Abstract

Let Λ be a finite-dimensional, basic and connected algebra over an algebraically closed field, and mod Λ be the category of finitely generated right Λ-modules. We say that Λ has acceptable projectives if the indecomposable projective Λ-modules lie either in a preprojective component without injective modules or in a standard coil, and the standard coils containing projectives are ordered. We prove that for such an algebra Λ the following conditions are equivalent: (a) Λ is tame, (b) the Tits form $q_Λ$ of Λ is weakly non-negative, (c)~Λ is an iterated coil enlargement