5 papers
Non-piecewise hereditary Nakayama algebras
Didrik Fosse, Steffen Oppermann, Torkil Stai
Happel and Seidel gave a classification of piecewise hereditary Nakayama algebras, where the relations are given by some power of the radical. Here we explore what happens for gene…
Partial Serre duality and cocompact objects
Steffen Oppermann, Chrysostomos Psaroudakis, Torkil Stai
A successful theme in the development of triangulated categories has been the study of compact objects. A weak dual notion called 0-cocompact objects was introduced in arXiv:1801.0…
Change of rings and singularity categories
Steffen Oppermann, Chrysostomos Psaroudakis, Torkil Stai
We investigate the behavior of singularity categories and stable categories of Gorenstein projective modules along a morphism of rings. The natural context to approach the problem…
Differential modules over quadratic monomial algebras
Torkil Stai
We compare the so-called clock condition to the gradability of certain differential modules over quadratic monomial algebras. For a stably hereditary algebra or a gentle one-cycle…
The triangulated hull of periodic complexes
Torkil Stai
In the terms of an `-periodic derived category', we describe explicitly how the orbit category of the bounded derived category of an algebra with respect to powers of the shift…