Irreducible morphisms in the bounded derived category via the category of complexes of fixed size

Abstract

We study which irreducible morphisms in the category of complexes of fixed size Cn(projA) with n≥2 and A an artin algebra, are irreducible in C[0,n](projA) or either in Cn+1(projA). Moreover, we determine which of them are also irreducible in the bounded derived category.