Criteria for prescribed bound on projective dimension

Abstract

We establish a prescribed upper bound for the projective dimension of a finitely generated module over a Cohen-Macaulay local ring (with canonical module) satisfying certain cohomological conditions. The central hypothesis is the vanishing of finitely many suitable Ext modules. We then derive corollaries which provide freeness criteria and a characterization of regular local rings. Finally, we raise two main questions related to our results; one generalizes a problem due to D. Jorgensen, and the other retrieves the long-standing Auslander-Reiten conjecture in the Gorenstein case.