Commutative coherent rings with $\mathcal{G}\mathcal{P}⊈\mathcal{GF}$

Abstract

For every field $k$, we construct a commutative coherent $k$-algebra admitting a Gorenstein projective module that is not Gorenstein flat.

arXiv commentCompletely rewritten: the earlier AI-assisted construction is replaced by a much simpler, elementary example