Gustavo Jasso (Bonn), A short proof of the defect formula for d-exact sequences.

Abstract:

We will recall Krause's proof of Auslander's defect formula. We will introduce d-exact sequences in d-cluster-titling subcategories and give an analogous proof of the defect formula in this setting. As an application, we deduce the (higher) Auslander-Reiten duality formula for d-cluster-tilting subcategories.