Seminars in Algebra (Spring 2026)

Tuesday, January 27th, 2026, at 14:15 in room 656

Speaker: David Nkansah (NTNU)

Title: Homological algebra without grading

Abstract: Complexes are central objects in homological algebra, and as such, grading is very present within the subject. But what if we discard the grading of a complex? This leads us to the notion of a differential module. In this talk, we explore how the homological algebra of differential modules can detect the finiteness of the injective dimension of a finitely generated module over a local commutative noetherian ring. As an application, we give a new characterisation of when such a ring is Cohen–Macaulay.