Vanishing of relative homology and depth of tensor products

Olgur Celikbas, Li Liang, Arash Sadeghi

For finitely generated modules $M$ and $N$ over a Gorenstein local ring $R$, one has $depthM+depthN=depth(M\otimes N)+depthR$, i.e., the depth formula holds, if $M$ and $N$…