Submission date: 14 October 2012.

Abstract:

We generalize the notion of length to an ordinal-valued invariant defined on the class of finitely generated modules over a Noetherian ring. A key property of this invariant is its semi-additivity on short exact sequences. As an application, we prove some general acyclicity theorems.

Mathematics Subject Classification:

Keywords and phrases:

Full text arXiv 1210.3855: pdf, ps.