Composite of irreducible morphisms in the bounded derived category

CHAIO, CLAUDIA; SOUTO SALORIO, MARIA JOSE; TREPODE, SONIA

JOURNAL OF PURE AND APPLIED ALGEBRA

ELSEVIER SCIENCE BV

Año: 2011 vol. 215 p. 2957 - 2968

0022-4049

We study necessary and sucient conditions for the existence of n irreducible morphisms in the bounded derived category of an Artin algebra, with non zero composite in the n + 1-power of the radical, for n 2. In the case of Db(H); the bounded derived category of an Ext-nite hereditary k-category H with a tilting object, such irreducible morphisms exist if and only if H is derived equivalent to a wild hereditary algebra orto a wild canonical algebra. We also characterize the cluster tilted algebras having such irreducible morphisms.